starter not "doubling in size"
I am new to all of this, having only made waffles and pancakes from my extra starter so far. My plan was to bake bread today but as it turns out I realize I have ignored something really important.
I have been reading as much as I can but don't understand it all, and I suppose some things don't register right away. Over and over I have read that the starter will "double in size" and somehow I managed to ignore that. My starter (which is gluten free) has been bubbly and has a wonderful yeasty somewhat sour smell but it only increases in size a little bit, maybe 10% which looks like foam that goes back down when I stir and feed. On and off it gets that black liquid on top so I know it's eating, though I don't think I ever starved it. My house is around 65 degrees, I don't have a consistently warm spot.
So my question is, do you think this is usable for bread if it is not doubling in size? Perhaps that is a dumb question.
I read that making the loaves smaller helps it rise, given that I thought about dinner rolls instead.
I was also wondering, is cross posting okay on this site? I know there is a forum for special needs baking but it is the sourdough starter that is the main question here so I thought most appropriate here.
Thank you!