If you intend to move her out, make sure you have plenty of time to supervise them and intervene if necessary, particularly if there is a ramp or some other physical barrier which might mean that they get separated and the broody has to decide which chicks to stay with and which to abandon. Just like pullets don't all start laying at the same age, so broody hens won't all range with their chicks in the same time frame. Most hens have imprinting with their chicks since before hatch so it's not unreasonable for this broody to take a little more time than usual to be confident she can marshal them before she encourages them to leave the safety of the coop, because she is having to bond with them further down the line than normal. I would put a scoop of dirt from the run or your garden into the coop so that she can teach them to scratch in it and pick up beneficial bacteria. It may encourage her to dust bath which is usually a priority for broody hens after they have been setting for so long and that may get her thinking about going outside.
Good luck with them
Barbara