Take a breath my dear, don't rush into everything.
Take her out to coffee, or tea, or shopping.
Have a girls day, just you and her.
Find a way to pull her away from everyone else and have a girl day.
Then just tell her, randomly or something on the ride there.

Your family seems far more understanding than mine, and that is what worked for me.

Except...it was pimple popping in the bathroom...but that's not the point.