when i had my 2nd baby, my daughter was 16 mos. it took her about a month to adjust to having another baby in the family and in the bedroom.
for us, it was good that her grandfather and daddy was here to give her undivided attention. and it helped that we reminded ourselves that she is still a baby too and not to expect her to act older than she is.
there was a lot of crying and daddy and grandpa did lots of carrying and comforting. i think it took a good month before my daughter was back to normal. i thought of it as an adjustment period
i think it is great that your husband is willing to take over the routines. perhaps while ur helper is around she can stand by and watch but let daddy do. don't worry, daddy just needs more practice. daddy and daughter will figure out what works for them.
i know the crying can be heart breaking, but that's how she communicates to you. just continue to be supportive, loving and understanding as you are now. she just needs time to adjust. and when the new baby arrives, she'll probably go through another adjustment period.
