2 month old with cold symptoms

So my 2 year old has had a could the past week or two and has been alllll over my 2 month old

Well now my 2 month old is sneezing is stuffy and has a small cough.

I read online if they’re under 3 months to take them to dr immediately just so it doesn’t develop into anything bigger. Should I take her in? Or wait and see? I’m sure this is a dumb question but wanted to see what everyone else things

Thanks!