In my opinion your kids will want to visit you even if you can't afford to take them out because they love you...are you close by transit?...maybe how old are your kids?

maybe arts and crafts if they are younger
rent a movie
go to a park if you're near one and have a picnic...bring a frisbee and a ball

bake things together

play a board game together

is there a recreation center near by?...maybe volunteer together to help the needy...I'm not sure
hope this helps