stray kitty

One day we notice this black older girl cat hanging around, so we feed her some milk and she came back the next day and keep hanging around so i followed her and she lead me to her kitten under our deck who was traped, so my husband got the kitten out and she took her kitten and went home i guess. But then the next day she came back for milk with her kitten. so now she and her kitten sleep on our back deck by the house every night.I wanted to take her in but she never is interested in coming inside so i let her do as she pleases, but i want to make her this outside home so her and her kitten are warm this winter!