Secrets among sisters

I'm the eldest of six children
Three girls and three boys
Nowadays we girls are close
But the boys still make alot of noise

Mariyah and I are the oldest two
Though we've been known to tell
Between the two of us
We've kept a few secrets as well

We haven't always been this close
We used to bicker and fight
But that's no longer the case
We could sit up telling secrets all night

We have a little sister too
But she is only six
Unfortunately she has started catching on
Learning all of our tricks

I love all of my siblings
But my sisters are the best
I trust them with all of my heart
They come before all the rest

We could tell some stories
Great memories in our past
I may not be their mother
But my god they have grown up fast

I bet you thought I'd tell you
But those secrets are mine to hold
I imagine we will keep those secrets
Until we are grey and old