Hi K. WoW you are definetly NOT ALONE and if that is a little comforting that is great. I also have a 3 1/2 and also a 15 month and expecting my third. My 3 year old like yours, have been strong spirited and strong willed since she was born. When she turned 6 months and older she did not want to nap, every day it was a tantrum to sleep, I would put her in her crib crying and screaming and leave, close the door and she would yell and scream until she fall asleep and I would feel the worse mom, but my consistancy gave her some sense of routine to follow and as she got older it got better. Now when she takes her nap and wakes up she does what your child does, she yells screams for about 20 to 30 minutes if we let her. I've noticed if she does not get her two hour nap she will wake up doing this tantrum scene, so if she does wake up before her time, what my husband does is tell her that he brought her a movie (she loves movies) and that they are going to watch it together. She walks over to the tv still crying loud, but as she distracts herself watching, she calms down. Strong will children demand more time, they need more activity, need more attention and are always competing for it and demanding it their own ways. Perhaps she misses her daddy, dad should film himself talking to each child, so you can play it for them daily as a treat for them and they can at least see their dad and he can speak to them. Our hands are full as moms, but God made us strong, we are definetly not the weaker sex, we are also loving, caring, compasionate and smart, use it to your advantage. Give your 3 year old lots of hugs and kisses and tell her you love her to reassure her that you will always be there. Do not beat yourself with what if's and move forward trying new solutions to this challenge. Continue putting her back to bed and reasure her that you love her and that you are close by. Hope this helps.
M.