DIPPY.
What I would say is this. Firstly it strikes a cord with me too, my family were sooooo hands on when ds1 was a gorgeous little new born , but as he grew bigger and bigger and more of a handful and lets be blunt bloody hard work I have to say that the novelty for want of a better word seemed to die off a bit.
TBH the honest the thing about "not being able to "cope" with the both of them at the same time, sorry to be blunt sounds like a load of old crap, and it sounds like she doesn't want to be arsed, not that she can't cope. Like you say she's had her own kids and I am sure is more than able of coping so as for going in to hospital then I am sure you have got nothing at all too worry about.
If you ask me, some "older folk" once they get to a certain age lose all the maternal/paternal feelings and instincts and just go into grey mode. Thats the way I see mine. Its the same now. I know exactly whats coming for the next year they won't be able to do enough for us, but after that and they turn into little screaming blighters the novelty will wear off again. But hey!
Mine live in Norfolk, yes 4 1/2 hrs drive away theres sth to worry about!!!