Is it normal for 19 month old to be sick every 2-3wks

[forevermore]

DD2 has had about 6-8 virus this year and last week was on penicillin for tonsillitis. It was her first course of antibiotics this year but still worried she is sick so often. Just as weight and eating goes back to normal she gets sick again. She mixes with lots of school children at Childminder is this a factor ? I am worried how she and we can keepig coping with this. She has had flu vomitting bugs and non specific cold viruses.

It was a struggle getting her to swallow the penicillin last week so we gave it for an extra day (6 instead of 7). And I also would try and give a bit more if she spat out a lot. She now has a temp having been happy all day and I'm worried the tonsillitis could have come back because she spat too much of the antibiotics out?

I mean 6 instead of 5 days

DS2 was sick constantly for the first 6 months at nursery, I actually ended up leaving work as I was ringing in sick every couple of weeks (not good for an optometrist with a full patient list!)
He had cold like things, tonsillitis, chicken pox, etc. Six months later it had slowed down a lot and apart from a constantly runny nose he's very rarely ill now.