Just going by the information we have from her parents, no other delays noted. IMO there are too many children diagnosed with conditions that are really not conditions but placations of nervous parents who push for a diagnosis when children are progressing on the "wrong" side of the curve but, still on the curve. The costs in money and time are enormous when common sense would tell you that she will walk when she is ready. Usually it is children who have found a very useful and efficient way of ambulating without walking who take longer. If she is off the curve then by all means, investigate but, she wasn't.
I have no problem with her mother seeking physical therapy if she can afford it but, I don't think it is a big deal that her father doesn't se it the same way she does.