A lot of the problems that we have with pelvic floor are because the nerves have been stretched, as well as the muscles. This means that we TRY to kegel -- and we can try really hard, but we may not be that effective. I went to a PT to help with my issues (and it helped tremendously) - she had me start out very very slowly. So for the first several weeks, you wont want to try doing anything sitting up -- too much gravity for those weak muscles. Lay down with your knees bent comfortably. Put your hand on your belly and make sure it stays relaxed. Now try and contract your pelvic floor to kegel, being sure to keep breathing, keep your abdominals relaxed, and your butt relaxed. ONLY your pelvic floor should contract. Do a set of 5 at 1-second on, 1 second off, and then rest 10 seconds. Repeat 5 times. Just concentrate on doing them right, not doing a lot, or doing them hard. (I know, it's tempting to move on). If you can easily reach, you can take one hand and insert a couple fingers into your vagina while you do it to gauge how hard you're actually contracting. You'll probably be quite surprised to notice that you FEEL like you're pulling very hard, but you can hardly feel anything moving with your finger. This is normal and will get better.
Anyway, the trick is to be consistent with these, and focus on doing them correctly, not hard or more. If you feel your muscles getting fatigued, stop. If you feel yourself starting to hold yoru breath or use your abs or your butt muscles, stop. Do about 5 sets of 5 in the mornings and the evenings for a couple weeks. Make sure you take a break between sets. As you get stronger you can move to sets of 10 with a 20-second rest between sets instead. And once you can do that easily, you can start doing some holds, where you hold the contraction for 5 seconds, then rest for 5 seconds, (do a set of 5, then 10, then 20 of the holds as you get stronger).
It will probably take you about 3-4 months before you're back where you want to be. In the mean time, be very careful about your intra-abdominal pressure when you do tasks such as lifting or baby wearing. If you feel like something you're doing is causing things to push "down there" then STOP. So anything that causes you to valsalva (google this if you don't know the term - too long to explain here) is bad. This goes for abdominal rehab exercises too. You can also start doing some "nauli" (google this - hard to explain), which can help w/ pelvic floor to move things back into the right place. Also, when you walk, be sure you've kept your lumbar curve in your back (ie stick your butt out a little by tipping your pelvis forward), since this will help your pelvic organs get back into the right place. Remember, your uterus is still shrinking down and things are quite mobile in there, so you've got a lot of time. Most of all, be gentle with yourself and remember that your body is still healing.