You need to get her examined at once by an orthopedic doctor.
She would need a full body bone review and blood tests to confirm mineral derangement if at all any.
I should appreciate your awareness that you noticed this such early.
Don't be panicky as it just might be very normal as infants have ongoing development of the joints till they are into their teens and beyond.
Caution: Don't try any massage
maneuver yourself or apply some unknown oil based therapies.