I've never found a male out wandering. I'm not saying they don't but I find females out exploring and going from pond to pond all of the time.
My first huge female used to go down to a neighbor’s pond about a half mile away for the summer and fall and then return for the winter and spring. I think she quit doing that once the male population got up to at least one mating age male. They seem to disappear in the heat of summer but they are just aestivating. They appear later covered in mud from the dark cool pond bottom. Lots of turtles surface from the deepest part of the pond when I call them for food then I don't see them again until I feed them again.
She is trying to find a perfect area to lay her eggs and they seem to have a need to go a certain distance from water and up hill a little. Probably to escape floods. They are river turtles. If she is still searching then she has probably not layed yet or she layed in the garden. A slight slope that is well drained is much preferred. They judge the quality of the soil and its temperature probably my scent and by feel. I have watched them finding a spot and they will walk a few feet and stop and hold their head high and look around and then lower their head to the ground and smell it a few times. I think they are looking for a rich organic well drained soil smell and the right temperature with their feet and chin. Since it's her first time searching for a nest site she is probably a little unsure of herself and trying to find the best spot she can because she hopes not only the spot will be good but she will want to return again and again to that spot thus limiting her vulnerable time on land in the future. My turtles haul out, go to their spots and then back to the water with no wandering. They just want to get the job done and go home. She is holding her eggs as long as possible in hopes that she can find that perfect spot that will hatch her eggs for years. She can't hold them forever though and eventually she will lay them wherever she can but you can imagine that she at least won't feel as good about it. She may have layed in your garden. You can bet that she is making a map of everywhere she has been. A turtle never forgets. And they always stop to look around.
