I have a 3 and half year old girl...she's suffering from swollen gum and ulcers on tongue and mouth..taking a lot of medication but all don't work?

This sounds: like a viral infection due to cocksackie virus (causes hand foot mouth disease) or gingivastomatitis due to herpes virus. usually will get better within a few days. important to keep her well hydrated otherwise f/u with pediatrician.

Sores in mouth: What medicines is she on? Does she have herpes simplex 1 infection? Is she able to eat and drink? Are the medications prescription or over the counter? I recommend you have her evaluated by a doctor if she hasn't already been.

Sounds like she has : One of the childhood viruses the almost all kids get It is not harmful but hurtful. Have her try cold things like Popsicles and icecream or suck on ice sticks. Five pain medicine that your pediatrician approves OV around the clock to keep her comfortable . It can last a week or so but should get progressively better

Workup and Mgt: I would suggest asking for cultures including viral cultures, a complete blood cell count and differential. It may be a local infection or in more unusual cases indicate an underlying immune problem.