Hope I can be of some help here...
My DD (20mnth) walks on her tip toes, and always has done. After a bit of internet reading, and some good old mn advice I did nothing til she was 18 months.
At 18months, I decided it was time to get the ball rolling and called HV. She suggested that I should do nothing til DD was 2 years, and then to see GP. I decided to see GP sooner rather than later.
GP asked a series of questions (aided by a helpful Dr's only online diagnosis tool). Essentially there were a few symptoms that meant tip toe walking merited further attention (I'm not sure if it needs to be one or more of these to investigate further). These were
- walking normally then moving to tiptoes
- pain / discomfort
- walking with one foot normal, and the other on tiptoes
- inability to put heel on floor
- continued tiptoe walking past age 5
On this basis my DD was investigated any further, and I was advised to come back if she seemed in any pain or if it hadn't resolved itself by the time she was 5.
Two months on and some people think they see an improvement in DD, but I'm not sure...
It sounds like your DD could do with some more investigation, so I'd take her to GP - after all, it can't do any harm.