If pediapred (prednisolone) is an immune system suppressant why would my one-year-old's dr prescribe it along with antibiotics for her diagnosis of bronchiolitis and upper respiratory infection? is this ok?

It's fine: Pediapred (prednisolone) is a liquid version of a steroid. This is good to decrease the inflammation associated with some uri's and reactive airway disease. If it is truly bronchiolitis(weird time of year for it) then nothing is going to make much difference. I would more question the antibiotics unless there is a suspected/confirmed bacterial infection. In summary, the Pediapred (prednisolone) is fine.

Short vs long term : The Pediapred (prednisolone) mimics a stress hormone we all make that helps us maintain the cell wall integrity & calm down inflammation. It is common to use Pediapred (prednisolone) in bronchiolitis & some other issues in young kids over a short 5 day period. Limiting the rx to several days avoids the immune suppression that occurs if you use it over weeks or months. I use it often for similar issues.

Pediapred (prednisolone): If you doctor prescribed pediapred, (prednisolone) it is either he/she suspects asthma or croup that is causing the upper respiratory tract infection.