Adopted By Her Mates The Alpha

Lily is a 12 year old girl, who's pack has been kill by a pack of rogues. Alpha Titus found her in his land, he found out that she is his mate. Alpha Titus adopted her, what happen when the bond is to strong? When she's 14 and start to feel like she is burning when she's not around him, but to young to be marked.
(Note this is not all of description and THERE WILL BE SEX IN THIS BUT WHEN SHE 16.)