Rumer Willis doesn’t care what you think ... in a blue denim jumpsuit and white-and-purple sneakers, with her blonde hair up in a half ponytail as she nurses from her mom and plays with Willis ...

"Merry Christmas from me and my tiny love and the Willis sisters," Rumer captioned the post. The proud mama looks festive in a red striped jacket with a matching red bow in her blonde hair.

Rumer Willis is making a major change—but so far ... tried on every version of myself (and every hair color imaginable), rearranged furniture more times than I can count, and even redesigned ...