Did I accidently use a racial slur??

I'm mortified.

So we had a yard sale this past weekend.

My 5 year old niece wanted to come to sell some toys.

Her name is Charleigh, but we call her Tati or Chacha.

Well she was helping me set up and some people had already showed up early.

There was a Latina lady standing next to my niece. And I called out for my niece and said "Hey Chachi bring me that box" my mistake I combined her two nicknames.

The lady turns and looks at me like im crazy and said "ok..."

I said oh no no, sorry I was talking to my niece. She then left with her kids.

I'm sorry if I sound ignorant!! Did I offend her?

Ugh, I feel so dumb.

Is Chachi a slur?? What does it mean?