I'm glad most of my dogs have been small enough to carry when they get old. I guess if they hadn't been, I'd just have to be a lot stronger so I could lift them. I mean, I'd obviously never leave them to sleep on their own after years of sleeping in my bed.
I slept in the floor with my girl the last few weeks. Couldn't do it all the time, and she didn't always want to cuddle as she got closer to the end, but sometimes she would get scared and need company to sleep well. But she wouldn't stay in the bed, so floor it is.
My cat isn't old or even lazy, but he's not a jumper (he prefers to hook his claws in something and drag himself up. I was told it was a quirk his dad had.)
So I built him ramps! He has ramps to the tops of things!
...and as soon as I installed ramps he began jumping to the tops of things that had ramps.
If she can't get up there by herself, it also means she can't get comfortably down by herself and she can't count on you being present when she decides she needs to, so I do understand her thinking.
That is what families do, they stick together. I have a 12 year old boxer/staffie cross and sometimes i have to help him up and down from beds, stairs and such...he weighs 45 kg so he is not a small dog either.