ZoE has free access to my bed whenever she wants.  If fact, many evenings, when I'm still up doing stuff around the house, she'll take herself off to bed.  I'll notice she's not been around for a while and I go looking for her, and there she is snuggled up on my bed snoozing away.
 
My bed is not crazy high...I can get in it without steps 

  So I just put a small bench next to it (the kind from a makeup vanity), and in front of the vanity bench is a footstool....so basically, I made "steps" using stuff I had around the house 
