Not sure why you would want to limit her mobility. Establishing hip strength and (as much pain free) range of motion are the two biggest things to getting her moving.
If he/she did rehab, a lot of that was established there. Depending on amount of time post-op and physician release, which again usually happens while in rehab, the total-hip precautions, internal rotation, leg-crossing and flexing past 90degrees, are less important. But then too, depending on the approach, if its anterior the precautions are no longer applicable to total hip replacements, even right after having the surgery.
Tim Williams, BS, HFS, PTA, KTP