Pups can continue growing till 8-9 months old - usually they've achieved their adult height by then. Menolly may just be one of those pups who has LONG legs - like my Bella, she was a little girl - but leggy - we called her Wilt because she liked to jump! She's still small - about 12 1/2 inches (if that) and less than 20#, both of her parents are small. Bella's mom is a tiny little girl - I don't think she's even 11 tall and has VERY short little legs - and her dad is about 12 1/2 inches - and 20#. However, you can't ALWAYS tell by the parents how big the pups will be.
JoJo's mom was a tiny little petite beagle lady, but her mom's full brother (not littermate but full brother) is the magnificent beagle on my avatar. He is 18 and about 53#. JoJo's pups are mostly average to small. Jack is built more like his grandsire - a more sturdy beagle, not tall, but sturdy - while Joe is very much like his grandma, Spotty, probably about 20-22# and trimmer tho they were littermates, Jack was always bigger than Joe. Angel is pretty small - probably about 12 1/2 and 18-20#. They all have the same sire.
She should achieve her full height by about 9 months, but may fill out after that.
Here's my leggy Bella Boo when she was about 6 months old. She looked bigger because of those long legs!