She's becoming ON OF THEM! Sofia Richie has worked hard the past year to integrate into the KarJenner clan and be accepted by the whole family. The 20-year-old has been dating Kourtney Kardashian's ex Scott Disick for two years -- that's like seven years in Hollywood time -- and she's gotten the okay from Kourt to hang with the former couple's three kids; she's invited to Kris' annual Christmas party; and recently she went on Kylie Jenner's girls' trip to Turks and Caicos. How much closer can you get?!

Well in addition to all that, she's gotten her lips plumped, her boobs done, and her nails are longer now -- all in an effort to basically morph into a Kardashian because, well, imitation is the highest form of flattery and the Kardashians love their minions to be copycats!

In fact, Kylie loves it so much she's make Sofia her official new BFF, according to a DailyMail report. After the ladies went on the Kylie Skin summer vacay together, they're inseparable and forever bonded, according to the rag's sources. After Kylie dumped Jordyn Woods following the cheating scandal with Tristan Thompson, she was on the lookout for a replacement ride-or-die and it seems Sofia fits the bill: "Sofia really helped Kylie through the emotional roller coaster during the Jordyn situation. She was really there for her and took her side through everything. The situation with Jordyn made them closer," says the source.

And since the fellow youngin' has so much experience with kids (Scott's), Kylie trusts Richie with her daughter Stormi: "Kylie also trusts Sofia around Stormi, which is very important to her. Sofia has been around since Stormi was born and Kylie feels comfortable with having her around her child after getting to know her better. They have now formed an irreplaceable bond."

These two have been spending lots of quality time together: "Kylie loves how fun Sofia is and has been inviting her over to her house more often to hang just the two of them. They love staying home and watching movies and cooking together while hanging with Stormi. Kylie knows whenever she wants a girls' night out on the town, she can always count on Sofia for a good time."

Sounds like they're dating!