How do I let go of our current nanny?

We have 6 month old twins and hired a nanny (recommended by a friend) to take care of them. She was doing great we thought until we had to hire this other nanny who filled in for her for a weekend.

This woman was and is like pure magic with them. The babies are calm, the house is relaxed, they love and eat some much better with her (even more quantities than they take with us which bugs me but it is so reassuring to know they are being well fed)

The current nanny tries her best but the babies just dont feel right with her, dont eat well with her, and kind of just adjust with her throughout the day. She also constantly keeps telling me babies are tired when they have just woken up from 9 hr stretch and puts them to sleep/or lets them play long hours saying she is tired but not sleepy.

I want to let go of her (she was on trial basis for about 3 weeks in December’25 and started officially last week) and start with the nanny babies love next week. If it were up to me, I would have given her a longer notice. I am just torn between wanting to do the best for my twins and start with the one they love asap and being considerate with the one to let go of.

Both nannys are kind of part time.

Current nanny is here 27.5 hours a week and charges $25.5 an hour and the nanny babies love can be here 31 hours charges $20/hr.

Current nanny is also here only in the afternoons on Tuesday and Friday which I have told her that this is a problem for us. This Tuesday I have even told her that we are getting someone else to help so lets meet on Wednesday.

Should I just say we are starting daycare? Or be honest!