state of a rose

My little miniature rose has some lower leaves turning yellow and then dropping off. I was concerned about this, but it also has quite a few fresh, new leaves growing

and some blooms opening

as well as a new tiny bud.

So I think perhaps the dying foliage is either from the overnight chill in my window, or because it is crowded. It's actually four little plants in one small pot, the roots are growing out the bottom. It needs to get split up one plant for each new pot. And set outside as well.