N.K.
I obviously don't know for certain what is wrong, but it is probably because of the baby. She may be young but she's already experiencing what she thinks is "neglect" because of the baby.
NO! You are not neglecting her!!! that is not what I am trying to say!
But, she probably feels that way since you've been put on bed rest. You're not able to play with her and take care of her like you could before, but she's still too young to really understand why.
It may be a little difficult when the new baby comes around, but you could make it easier by making sure that you spend some time with just her. Go to the park, or take a mommy and me class together, or just spend an hour playing in her room with her.
Another thing that you should do is have your husband spend time alone with her now.
When I was pregnant and not able to do the usual things with my daughter (she was 4) my husband started taking her on dates. They would go to a movie or the park or somewhere else that she picked and then they went to dinner. She loved it because it made her feel special, and it's something that they still do.
Your daughter is a little young for "dates" but he can take her to the park too or just spend a little time around home doing nothing but playing with her, snuggling or spending an hour reading stories.
Good luck with the new baby and with your daughter.