Nathalie when dad died, mum had hassles with my uncle and a couple of aunties, they wanted different things and thought mum would just give into them, but she stood up for what she wanted. In the end she told my Uncle that if they didn't like it they could just forget about coming to the funeral, it wasn't about them it was about me her and dad.
Also to save mum haveing to spend money and stuff, we just had biscuits/coffee/tea at the 'reception room' at the chapel, which is what alot of ppl do.
It's really sad that funerals bring out the worst in ppl sometimes, they only was I reakon for things is for your mother to say that it can be held at a cafe or somewhere and everyone pay for their own food and drinks, and if she dosen't say anything, well then she has to cop it all and the expense.

*hugs* I'm sorry about loosing your grandma too.