Squishy lump on ear flap

[LikeTheShoes]

I'm looking after my parents' golden retriever for the weekend and I've noticed she has a squishy lump on her ear flap. Dr Google informs me this is probably a hematoma. She seems fine, but it has definitely grown since Friday and is warm to the touch. It doesn't seem to be bothering her though. I am pretty sure she is insured but I don't know the details. Am I right in thinking this can wait until they are back on Tuesday? Or is this an emergency vet job?

Vets during the day(should be more affordable versus night calls) if possible. Haematomas often appear due to an underlying ear infection(shaking and scratching the head causing the blood vessel to rupture in the first place and if she continues to shake her head the haematoma can grow and the larger they are the longer the anaesthetic needed if it goes to surgery... plus ear infections when I've had them feel awful so pain relief would be no harm.