VioletSky
You can't always rely on a struggling parent who is suddenly having a £50 a week budget deficit to make good choices.
It doesn't necessarily make this a bad mother or make her cruel.
She has child, suddenly all the responsibility of providing for that child rests solely on her shoulders. She has a smaller budget to do so.
She is trying to force Dad to do the right thing and start supporting his child again.
She has gone about it the wrong way but there is not a right way option for her here, it is solely dependant on Dad.
She may be incredibly stressed and struggling to cope with mounting bills or going without necessities.
That deserves a little empathy.
Dad needs to get stable and pursue this through the proper routes, starting with mediation where hopefully they can come together and co-parent effectively in future
Do you think a mediator would come from a place of telling dad and grandma that mum is cruel and doesn't have her child's best interests at heart? No, so neither should you, you will create animosity between these people which will worsen the situation for the future.
So many suppositions.
It is just as wrong to assume a mum is acting in the genuine interests of the child as it is to assume the dad is at fault because of his financial difficulties.
The mum may in fact be denying the dad overnight stays because if the child stays her payments would be reduced.
The mum may be using the child to punish the dad for his behaviour.
The mum may in fact just want more money .
Whatever the case, however stressed or short of money she may be, using the child as a weapon is completely unacceptable.
It's also completely illogical and counter productive. After all if you are short of money, someone feeding the child for a day, accommodating them over night and perhaps buying them things can only help with your financial difficulties.