Nanny misrepresented experience

I could really use some advice, please. We hired a full-time nanny who has worked for us for only one week. She said she had newborn experience and it was my bad for not asking more questions or calling her references (dumb of me, I know, this is definitely a learning experience and I will do things differently in the future). It became clear on the first day that she had very little experience with newborns—holding the baby awkwardly, does not know how to burp the baby, or even that there is such a thing as newborn cues for sleep or hunger. I tend to be overly trusting and want to help people. I have spent a lot of time trying to show her what to do with the baby but it is stressful. I hired someone so I could get a break and take naps but I end up more tired than if I was alone. She also spends a lot of time sitting on the couch on her phone and does not help much with my other child when they are home.

It is the holidays and I feel bad firing her without severance. I had written out the schedule for two weeks and am paying her for 35 guaranteed hours a week. I did not have her work that many hours last week and I offered to give her Christmas Eve, Christmas, and New Year’s Day off paid. My husband thinks I should fire her without severance because she lied about her experience. I feel like since I already said the schedule for the next two weeks that it would be rude to go back on my word. We do not have a contract. I am considering explaining it’s not a good fit and we need someone with more experience and letting her finish out the two weeks. Another option my husband thought of is to explain why we are firing her and give her the option to continue on a part-time hourly basis for the next two weeks.

Please advise, thank you in advance!