First,,,You can sign..it doesn't matter if it is reinforced in the other areas of your childs life! She may pick it up,,she may only understand and not mimic,,it may just be a hint to her that she can learn to communicate in non-verbal ways. Don't let others totally take away your parenting power! Even if you only have one sign you make as many times as you can in one day, it is still worth it!
We have a 15 month old boy, he is my third. I have used some signs regularly since he was about 9 months old. (I had never heard of signing with your toddler with my other children.) A couple he uses in his own way,( and often sayes it as he signs) ,he uses butterfly, milk, mama, more, and understands a few more. But he is also becoming increasingly verbal.
I think he is communicating so much better than my older two did at this age, but it has really taken off in the past month. You are almost there! I have a hunch your daughter will surprise you soon. Just keep giving her lots of "imput". Name items, talk about stuff, chit chat a lot.
As for the whining,,ours will communicate what he wants sometimes,,but still can really whine! He seems to do it more when I am the one fuss to. he is also wanting to nurse constantly sometimes, or do the annoying "check in" nursing, where he wants to nurse for 30 seconds or so every 3-10 minutes,,I feel like I am always unhooking, hooking, readjusting..
I am feeling as if he just is working so hard to stretch out his world, explore more, learn more...he just needs to reassure himself a lot. That is ok! I just need to not worry,,and empower myself to meet his needs. There are many times I feel as if I need to be doing "something", cleaning, cooking, so on..but just try to let it go when he needs me. Tomorrow he will be 10, and he won't need snuggles every 5 minutes anymore! (I know,, I have a 10 yr old and 7 yr old.) I will so miss it when that time comes!
I also suggest "babyproofing" as much as your living situation allowes. Josh really likes to be able to roam the house,,we let him cruise, explore, to his little hearts desire. If he can't have it, we do our best to just keep it where he can't see it, grab it, so on. Just remove as much of the temptation, and then encourage safe exploring as much as you can. He is climbing like a fiend now,,so we let him go up and down the stairs ( he has been doing this for a couple of months), gets up on the couch to look out the window, up into the chair. We just try to keep him safe!
OK,,sorry I have made this so long! He is actually napping..it is rare I get to type with two hands,,let alone uninterrupted!