Hey gal, so very sorry to hear about
your Mom. What kind of surgery is being planned for your Mom? So, it sounds like your Mom had a birth defect with only two valaes all these years. Makes you wonder how she made it this long before having problems. I will say lots of prayers for her. I have been thru the surgery with my Dad and then again with my brother. My brother was only 52 when they replaced his aortic valve. Both of them had high BP out of control for years and it damaged the valves. I have followed in their foot steps with valve problems relating to the uncontrolled BP.
My sister came and helped take care of my brother after he was released from the hospital. He just needed help with meals and things like that. My sis fixed his breakfast and lunch then the wife cooked dinner. I think you will be ok, I don't see how you would have to liift. For one thing when people have open hear surgery another person cannot pull on them, it would kill them with the pain, their sternum is cracked open. Before being allowed to go home your Mom will be taught how to get out of bed on her own and how to get up from a chair. My brother woke up with a teddy bear on his chest and he was taught how to put the bear to his chest when he moved around. The pressure against the chest helped him not hurt when he moved around. Before my other friends were shown how to hug a pillow to their chest. I think the bear worked better. By the way, my brother still has his bear. He used him for about 3 months. Because my brother's bed was high off the floor he slept on the couch in a sitting up position, it was more comfortable than trying to lay down.
If there is any other kind of lifting involved save it for one of the other family members to do when they get there. Trust me if you tried to pull or push on your Mom after open heart surgery, she would shoot you, lol. take care and keep us posted about your Mom. Hugs.