Head pain, ear infection, anyone have experience with this?

My mother (age 65) had an ear infection which was not treated fast, and after that got head pain. She also has swelling above the eyebrows and on the forehead. Oral antibiotics helped slightly but didn't cure it. When she had IV antibiotics for unrelated hip surgery, she seemed to get better for a while but that was just one dose. Obviously we suspect an infection, but tests such as a blood test, MRI, and CT haven't shown anything useful. It's almost impossible getting doctors to listen to her without test results. Has anyone had experience with something like this and what could cause it?

It doesn't seem to be New Daily Persistent Headache because of the swelling and because antibiotics had some effect.