Repeat chest infections/ill all the time!!

Hi

I feel really sorry for Maiya as since she's been born she seems to have suffered with loads of illnesses!! she's had ear infections and three chest infections (plus colds etc). I try to get her to eat veg - also make pureed veg pots fruit pots and mix into her food to try ensure she gets enough vits!! She's just been given another course of antibiotics. was just wondering if this is normal at this young age (14 months)? she does go to nursery twice a week but I wonder if it's just that???

does anyone have any good tips? she loves banana but cut back on that recently as she was a bit constipated and read that banana, eggs and cheese can be binding. sometimes i find it tricky to find healthy foods!! Is diluted orange juice a good idea??

any suggestions much appreciated

thanks