Grandma is visiting and has a cold

Sian • Married 6/10/18 Mommy to Reid Thomas 6/20/19 TTC #2

So my baby is 5 weeks and my grandma has traveled from England to California this week to see him. Bad news is she has caught a cold on her trip. She arrived Monday and she didn’t tell me she didn’t feel well until after she held my son. I made her wash her hands before she held him. And then after she said that I told her not to hold him. I took her to get medication today and she hasn’t held him today. She’s visiting until Saturday and is sharing a room with my Aunt. I’m terrified that she’s going to get my baby sick and also me sick 😩 I can’t just tell her to come back when she feels better since she’s traveled internationally. She’s also 82 so she’s probably never going to get the chance to see him again.. how do you think I should approach this situation? Just tell her to wash her hands before she holds the baby or tell her that she can’t hold him at all? Am I over reacting?