Assuming you mean regenerations, it's at least two, although the exact number is unknown.
We saw the little girl regenerate in New York, but we didn't see what she regenerated into. Mels, in the beginning of "Let's Kill Hitler", said the last time she regenerated, she ended up a toddler in the middle of New York, which implies she was the next regeneration after the little girl. However, this is controversial, because it leaves a 26 year period where she aged very little, followed by her aging at a normal human rate with her parents, so some people have assumed an in-between regeneration.
Of course Mels regenerated into River Song in "Let's Kill Hitler", making that at least her second regeneration/third incarnation.