"to grow up"

when she asked what would I be with another person as a couple for, I said: "to group up".

When I said so I was not talking about how tall I was, cause I know that fact it's done.
Instead, I was talking aobut growing up on feelings, growin up on emphaty, on experiences, on spirit, on heart.
On that sense, growing up means a lot of things, things to be done togheter helpped by companionship.

After a little while, she said: "I've already grown up", and I realized that she hadn't understood what I meant, so my answer might have sound stupid.
Actually, thinking a little more about it, I´m sure that was the case.