If you have $50 you could easily set her up in a storage tub.
How old is the snake? I gather that she is a little bit older since you got her from someone else?
I will just write up a little shopping list for a juvenile BP tub setup.
32qt tub: Found at walmart, meijer, bed bath and beyond, target for about 5-$10
Under tank heater: Found at major pet stores for about $20
Accurite thermometer/hygrometer: Found at walmart, lowes, home depot for about $12
Light dimmer: Found at lowes, home depot for about $10
Hides: Dollar store opaque plastic bowls for $1
A smaller enclosure is the best thing you can do for your animal right now. a 75g is way to big for any ball python. You are going to have problems keeping the heat and humidity up.