First off, CONGRATS! Not many people get to witness the nesting behavior of turtles, and it's an amazing site to behold.
The single most important thing we can do is NOT disturb her while she's nesting. When turtles are disturbed from nesting, it forces them go find a new location, and this is often a very dangerous feat. There's many factors that came into play when choosing this spot, and now she has to start the process over - traveling far, often across roads, risking herself and her eggs.
The best thing to give her space and keep pets clear of the area. It may take a while, but soon she will be on her way, and you may also have just saved her life.
Here's a few additional things to keep in mind -
Since turtles do not receive parental care, she will not be returning to the nest this year. Hatchlings will typically emerge around August/September, though painted turtles may overwinter in the nest. After emergence, they will make their way to the local wetlands.
Gravid painted turtle who was interrupted laying her eggs.
Turtles often spend an entire evening digging a nest to lay their eggs. Females dig deep into the ground with their hind legs, deposit eggs, and then meticulously cover the hole back up. Ideally a nest be left undisturbed, but the eggs are protected deep down there, so even if it's in a regularly used location, they should be safe underground. Keep an eye out for hatchlings emerging in early Fall.
When possible, turtles often return to the same nesting locations year after year, so it's likely this turtle has used your home for nesting in the past - they are discrete so it's easy to go undetected. They very particular about where they nest, so even if it seems unideal to us, she's taken a lot into account when choosing this spot.
Most turtle nests get predated. If you find egg shells outside of the nest, this is a sign the eggs have already been predated. Skunks and raccoons are particularly adept at finding nests.
If you're interested in protecting the eggs, reach out and we can help with tips, but this does take regular monitoring or you could do more harm then good.
If you're concerned about the location and really want the eggs moved, know this is a risky process that may result in no eggs being viable. It is best to let nature take it's course.
These are just some tips, but please call a wildlife rehabber if you have an uncertainty about a situation. We're here to help!