Wearing a mask with 4 month old

Please don't hate on me for this post. Just genuinely curious about other moms thoughts.

My LO is 4 months old and now I have to return to work from my leave. She will be going to a center 2 days a week. And masks are optional at this facility. The only teacher that still wears a mask is her nursery teacher. They are all vaccinated. I'm vaccinated. I had covid while I was pregnant. I'm breastfeeding her.

ANYWAYS, I'm just concerned about her not being able to see half her teacher's face while she's so little. I thought babies heavily depended on seeing us and our expressions for development. Should I be worried about this? I told the teacher my feelings about it, but told her I also respected her decision on what she thought was best for herself and her family at home. I'm just torn. I could look for another center in the area but there's year long waiting lists.