question!??!

[Fisher]

I had a 26 day old gerb with a pretty severe respiratory infection.  I have been giving her antibiotics for about 5 days now.  She is doing much better now at 31 days .  She is eating food, drinking a little from the water bottle and really loves to drink the antibiotic out of the dropper!!  She is still half the size of her 2 sisters but her fur is starting to grow thicker and her eyes haven't crusted over since I started the antibiotic.  She is also ALOT more active then last week.   My question is , how long should I continue her on the antibiotic.  She had the infection pretty bad ( real loud clicking and eyes crusted shut and lethargic) so I don't want to stop the meds before it is 100% cleared up.  Also , when should she catch up in weight with her sisters or will she ever??   Thanks,   Sara Fisher