I've namechanged for this so as not to connect my DH with my MN name.
Everything sashh said. The pillow reference made me smile, as all the heart patients at the hospital Dh went to get a heart-shaped pillow, signed by the nurses, to hug when they cough. Important when in a car, too. We still have it.
My DH, 56 at the time, had a quadruple bypass within days of indigestion-type pains. We are in Au but I expect the form is much the same in the UK.
DH was not let out until he was off oxycontin (hillbilly heroin) and could walk round the ward. They get them on their feet as soon as. It's all about off the drugs and on the feet. He was out 8 days after being admitted for an
angiogram.
At home I stayed off work for a week to tend. We are lucky and have bedrooms on the ground floor. Stairs are a no-no for some while. He was white as a sheet, lost muscle tone markedly and very cold. Make sure your mum's bed has plenty of throws, even in the summer.
DH had a set distance to walk each day, which he followed religiously. No driving for a set number of weeks.
Meals small and frequent.
Lots of hand washing and take care re dressings on the wounds.
Does your DM have a dog? Take care with first meetings to avoid jarring.
Your DM's hospital may offer rehab sessions which are also helpful. In terms of info, they didn't tell us anything we didn't know (not because they were low level, but we are well-read) but the camaraderie is very good. I went to every one. This is important, too.
I hope all goes well for your DM, blondegirl. 