I think in todays circumstances it can be difficult to get doctors to listen. I would recommend that you keep a diary of all the odd things that she does and then send a letter to the doctor outlining all your concerns before an appointment. That way it will be easier for you to convey your worries.
It can, unfortunately take a few months to get to diagnosis at the best of times and, at the moment, all routine appointments at hospitals (and that will probably include memory clinics) are being put on hold to open up capacity for coronavirus patients.