Estimated adult height for 16 yr old girl, period at 15 yr 0 months, dad 5'5 mom 5'4.5 .. currently 5'2.5. she looks pretty much fully developed. ?

Target height: Target height range for female with parent heights dad: 5'5" mom: 5.4" Target height would be 4ft 11in to 5ft 5in At age 16 & depending on what stage of puberty she has completed there may or may not be a little more room for growth. Bone age assessments can also determine if more height growth is expected, but this is not done routinely unless there is concern for an underlying endocrine issue.

Likely finished: The estimated final height of a young woman is the average of parents less 2.5 inches, give or take an inch. With your reported data that places her expected final height to be 5'2.5". The hormones that trigger puberty and menses also trigger the final growth and closure of growth centers. A single x-ray of her wrist/hand would reveal growth potential. I would consider her likely finished.