Hi, she should take some multivitamins with Vitamin C, you may consider and ayurvedic preparation like septilin comma and make sure that she takes the flu vaccination as well, beyond this regular handwashing is important and please avoid antibiotics as most of these infections are likely to be viral plus the antibiotics will reduce immunity

Hi. From the history i feel she is having allergic component so you might have to consider starting her on inhalers after showing to a respiratory physician . Start her on seacod capsules which will boost her immunity. Take anti allerguc precautions like no sweeping or dusting in front of her.