Oh I love this! My son is now 20 years old and some of our most special memories are when I took him on a “date”. I taught him to do everything that hopefully he would one day do on a date, so things like opening the car door for me, considering getting flowers, how to make conversation at dinner. And then, it was about me, as a mom, getting to know more of his heart, hopes, and dreams, and just giggling together — letting him know how much I cared. I did the same thing with my daughters.
Low cost options are having a picnic at a local park (or even in the front yard, for that matter), going for a bike ride in the neighborhood, etc. We also have a really cool public library here in town that always offers free or low-cost events, such as locally produced plays or musicians.