Sinus infection

I have a sinus and ear infection and was prescribed antibiotics yesterday. I told them I was nursing and they said this was fine, some of the antibiotic will pass into the milk and baby girl May get some diarrhea like me from them. This is the first time I’m taking antibiotics since probably highschool, and I know you can get yeast infections from antibiotics. So my questions are: WhAts the likely hood of that happening? Can baby girl also get one? I know they say eating yogurt can help fend off a yeast infection, so how much do I need to eat? I should’ve asked all these questions yesterday at the dr but I was so miserable I couldn’t think. TIA!