Mom isn't very pleasant in the mornings. Sullen and defiant would be the best descriptors. By late afternoon she usually cheers up and wants to interact instead of shutting herself off in her room. It seems as if she has reverse sundowners. Anyone else experience this? I've also thought it could just be that she's not a morning person and it just takes her a while.
It may take your mom a few hours, into the afternoon, to settle into a routine. Stiff joints loosen up and Morning Fog dissipates and she’s ready to face the day.
Respect her privacy and let her stay in her room as long as she needs. When she makes her daily appearance, greet her with a smile and a snack if she wants one. If she becomes too cantankerous and out of sorts, make sure to have her tested for a urinary tract infection.