Could be,,,anytime the ankles retain fluid it's either pulled muscles or god forbid the heart but not picking that up ...I think it's her walking , does she walk on cement or dirt? Good luck
The answer is that the problem is potentially serious, and should be evaluated by a physician. Fluid retention, kidney failure and heart faiilure are potential etiologies, although uncommon at age 30. From your observations, it is difficult to determine if the problem is edema (caused by fluid retention) or simple swelling of the feet, secondary to exercise.
Pls get blood pressure checked.Reduce salt intake but maintain same routine and check if problem subsides.
No matter how old your daughter is, getting swollen feet and ankles should be investigated by the doctor.
Advise your daughter to always wear comfortable and supportive shoes. Tell her to elevate her legs and feet as much as possible.
Swollen legs and feet can be caused by a number of reasons, from hormonal problems, circulation (heart) and kidney problems (and kidney stones) as well as problems with the lymphatic system.
If she does consume a lot of salt, it would be a good idea to reduce this.
The doctor will be able to check your daughter's blood pressure and examine her to rule out any problems.
Even though there is swelling which may be due to fluid retention, it is still important to drink plenty of water.