Consider making another "room" out back. With a few screen-type potted plants and a few chairs, you could have a whole additional sitting area (perhaps?).
For the bathroom, it is much cheaper to pay someone to install bathroom wall supports for your mom. Add them to the tub and near the sink. Help her to walk to the bathroom, get a four-point cane or another (collapsible) walker for using inside the bathroom. They also have metal supports which sit over the toilet for helping to sit and stand independently.
Make a special "nest" beside your bed for your daughter for when company comes. We kids always slept on the floor when we visited family, or when they came to visit us.
Decluttering a larger house is just harder because you have MORE stuff, ime.
It sounds like you'd like more socializing time and space. Your plate with school and a young child and house care sounds full! Perhaps, hire someone to help with a big clean a few time a year, before overnight guests come to visit. All of the above together is cheaper than additional debt.
I voted for cram another kid into the mix. But, that won't help you get more time to socialize. And I am an extrovert and understand the *need* to be with other people. Are you
wanting to "finish school and get a good paying job"? Or to have more kids? More kids won't get you a less cluttered house.

Pat