When will my daughter start her period? She’s 12.... I was 10 when I started. When should I worry? ?

I think you're a troll, because while starting at 10 is somewhat more common than it used to be, it's still fairly unusual.  12-14 is much more common.

There's nothing to worry about.  

By the way, it doesn't matter how tall she is; it matters how much body fat she has. If she's still pretty coltish and skinny, it could be a while before her period starts.  One of the reasons some girls are now starting at earlier ages is childhood obesity.

But I still think you're a troll.

Worry when she’s over 18. Yep, you heard me. 8-16 is the standard age for getting your first period, my friend knew someone who didn’t get theirs until they were 17 years old.

I have 3 sisters.

We were all different ages when we started, varying from 11 to 16.

Generally, if she hasn't started by 16 a health check is recommended but anything up to 18 is still classed as normal.

If you take a picture of her vajay jay and post it then I'll be able to tell you when the period will start. I've just messed up another keyboard in anticipation of seeing it.

Why would you worry?  Everyone isn't alike and just because you and your daughter are related, it doesn't mean that her body is maturing as fast as yours, may have.  My mother didn't start her period until she was 16, and my sister was 14. I was 12 or 13.  We are related, but we aren't alike either.  

They say puberty is starting earlier and earlier in children because of all the hormones used in our foods.  I believe it.