Care for Pregnant and Sick Rat

[Mother of Mischief]

I got a young, pregnant rat from someone who didn't know she was female and put her in a cage with their male rats (woopsie). I have her in a birthing cage because, according to my that person's account, she should be reaching about day twenty. However, I've noticed that she a has started sneezing and has a very soft click to her breathing. I have some antibiotics on-hand, but I can't find any resources online with any guidance on how to treat a pregnant rat who is sick. Are antibiotics even safe? Should I just forget about the kits and focus on the mom?

If you have relevant knowledge and/or experience, please advise. Thank you!