The Kardashians Are Cool With Kylie's Pregnancy...

Kylie Jenner is having a baby before she's legally allowed to drink, but her family is fully on board ... TMZ claims.Their  Kardashian sources tell them, the family doesn't view Kylie as a 20-year-old. They think her age is both deceptive and irrelevant, because she's developed a maturity way beyond her years.

Right or wrong, the family feels her success in business and financial independence gives her license to do what she's wanted for 2 years ... to have a baby. The fam was shocked at first, but is accepting.

So the question ... why didn't she have a kid with Tyga? We're told their relationship was never solid enough for a baby ... at least that's the way she felt.

That said, she was eager to become a de facto stepmom to Tyga's son, King Cairo. And she's an involved aunt to 6 kids.

As for having a baby with Travis ... she got pregnant within 2 months of starting to date him.

What they don't know ... whether this was a planned pregnancy or not. Either way, they are told Kylie immediately embraced it.