You can try other ABs but please do understand that none of them may actually clear it. Because it's likely that her tubes simply can't drain yet. So the infected fluid / pus etc can't get out, so as soon as an AB clears it, it'll simply pop back up unless and until the ears can drain.
Typically there's three ways they drain - surgery/grommets, a burst eardrum, or she grows out of it.
Keep taking her to gp and ensure they log each infection in her notes. She may eventually qualify for grommets.
Until them, pain management is really important. Are you dosing her with paracetamol AND ibuprofen? She needs both. Ask the GP to prescribe a pain management regime in detail - exactly what doses, timings. At NO point should the medicines have any time to wear off.
My DS had this at same age, at one point a continuous infection for almost 4 months. The ABs were being constantly reconsidered, changed, etc but nothing actually dealt with it except surgery and then him growing a bit.
I was advised to dose ibuprofen + paracetamol, highest possible dose of each, alternating every 3 hours so that they overlapped. That would let him sleep.
Good luck. It's a horrible time. Xx