I can relate to the knee thing...

When quad pug Obie had knee surgery I put my mattress on the floor because he always slept with me and I didn't want him jumping up or down.  The pugs loved it at that level, but my old jock knees....

Glad to hear Misu is doing so well.  I bet she will be able to get up and down the bed when she is full grown and stronger. Kitty tripawds have something that pups don't have- very sharp claws!  You could also build her a little stair case, or put some boxes or pillows together to make it easier for her.

I build several small staircases for my Tri-pug Maggie.  She steadfastly refused to use any of them during her four years on three. 

Karen