Dependent Care Credit (Tax Question)?

My wife and I got married last year. She didn't have any income last year but did a lot of volunteer work. She takes care of our 3-year-old daughter but we pay someone to watch her for 2.5 hrs twice a week (during which time I am working and she is volunteering). We also pay for her to go to daycare two days a week for a few hours (I am at work while she is at daycare. My wife doesn't often volunteer while she is at daycare but she sometimes helps at the daycare in exchange for a discount on our bill). Is there any way I am missing that we might be eligible for the dependent care credit? Or are we simply just not eligible because she didn't have any income? I want to be sure before I file. 2017 I was eligible because we weren't married yet and I filed as head-of-household and claimed them both as dependents.