You've diagnosed what's wrong-- a disconnect between you and the kids. Now's the time to fix that, before the baby comes.
Are you not connecting because you're pregnant and exhausted from single parenting? Or is there something else going on?
Regardless, the answer is pretty straightforward. Time with each of your girls, one on one, every single day. Here's a link about how to do that: What's So Special About Special Time?
The other answer is playfulness. No child can resist an invitation to play. So if you need the girls to do something, connect with them first. Make it a game. Do the chore with them.
Should you have to do that? Well, it would be terrific, obviously, if you could request that your girls do something and have them do it. But that isn't what is happening, and you can't actually force it. All you can do is create the kind of relationship with your girls that has them WANTING to do what you request, because of their connection with you. Because, bottom line, you can motivate them with force, or you can motivate them with love. As you say, who wants to live in a house where you have to yell? Instead, get their attention by being playful. Here's an example of lots of ways to do that:
No Shoes, No Shirt, No Power Struggle!
Especially after your baby arrives, your two older kids will seem practically grown up. But they aren't. They're very young, still. Even if they aren't showing it, what they want more than anything is connection with you. So if you want something done, and you can connect with them about it in a positive way, they'll feel motivated to do it. Here's another article that I think will give you practical ideas:
But How Do I Get My Kid to LISTEN?!
What about when there is a natural consequence, like the wrong shoes at dance class because the child forgot? You commiserate completely without blame. You resist the urge to say "But I told you to get your shoes." She knows you told her; that will just make her feel attacked on top of feeling like a failure because she forgot, and that will make her want to attack back by blaming anyone but herself. Instead, you say "Oh, Sweetie, I am so very sorry we don't have the shoes. Do your best without them and I know next week we will all do a better job remembering them." You can bet she will.
What if she has a meltdown because she doesn't have the shoes? You remember all the times you've messed up and forgotten things. You ditch your guilt for not reminding her, because that will make you want to blame her. And you summon up all your emotional generosity and shower it on her, saying "I know, it is so hard, you are so disappointed." You help her by explaining with her to the teacher if necessary, that "We're so sorry we forgot the shoes, next week we will remember." The next week you partner with her with a light touch, "Dance class today...and what do we need to remember? Let's find those shoes right now and get them into the bag, ok? Do you need help? Here's the bag on the table, can you get them right now so we don't have to be nervous about forgetting them?" You have turned a lesson into an opportunity for closeness and partnership. And she's learned a lesson.
But that is a natural consequence. Taking away toys temporarily because they were left out is not a natural consequence. It is a parent-contrived consequence, otherwise known as a punishment. You may think it is reasonable, but you can bet your kids don't. And you can bet they take it as evidence that you don't really care what they want.
So in an instance like this when some toys are left out after clean-up, does it really matter? (I would say, not nearly as much as a peaceful house.) But if if does, then you consider that you need to help your kids get in the habit of completing the job.
Should you have to do this? Well, no more than I should have to "teach" my husband that cleaning up the kitchen includes wiping the stove, meaning that it's natural that we have to continue to work with those we live with to refine our mutual understanding of what each of us considers a complete job. Unfortunately, these kinds of discussions are easily misinterpreted by the other person as our not appreciating all they HAVE done, to focus on what they haven't done. Since we want to increase, rather than decrease, motivation, it will work best if this is done as connection rather than correction.
So you zoom in with the kids pretending to be robots on cleanup detail. As robots, you survey the scene, noting all the toys that WERE put away so very well. Then you ask, speaking in your robot voice, "What about this toy? Does it belong here?" Your kids will giggle and race to put it away.
Should they have done it to begin with? Sure, but they're kids and this is your priority, not theirs. So you got the lucky chance to use this as an opportunity to connect with them. AND you get a peaceful house. AND the toys are all cleaned up. AND because you aren't punishing, your children are more cooperative and better listeners. AND If you do that for a week and make it the most fun game ever, your kids will love being robots while you watch in the future. A month later, they will be cleaning the room well while you are busy changing the baby, because that is now their habit.
Finally, what about you? It can be hard to "go the extra mile" to connect with your kids and maintain your playfulness when you're the only parent on, 24/7. And when you're pregnant and tired it's positively heroic. So taking care of you is critical. The more you can do that, the more you'll have to give your kids.
You mentioned resources. Anything that someone else can do to help you is great, so that you have time to take care of you and connect with your girls. And having a mother's helper or someone come in to play with one of the girls while you have special time with the other as often as possible would be very helpful. Otherwise they are always sharing you. Every child deserves some time when she doesn't have to share her mom, every single day.
One last thought. With three kids, some things are bound to get lost in the shuffle. You'll be getting your phd in not sweating the small stuff. Think of this as your initial practice.
Blessings to you and your growing family!
Edited by DrLauraMarkham - 2/11/12 at 8:39am