Breastfeeding

I just had my baby 3 weeks ago and I’ve been breastfeeding since. I also have a 2 year old who I only breastfed till she was 3months due to not latching on properly.. anyways today she woke up with a fever and throwing up and I was wondering if I could pump and give her in a bottle my breast milk maybe I’ll help her since breast milk helps in many things.. sorry might sound stupid but it’s a serious question lol thanks