I have a 6 month old pup that is measuring 20 in. right now. Is this about the right size for her age? Her mother is 21 in. and the sire is 23 in. At what age do the females stop growing? TIA

Try to relax and don't measure her, you will be surprised how much she grows when you are not worrying over it! Measure her when she is at 18 months.

They stop growing once they have their first heat. Just like human females once they hit puberty

I have a bitch that grew after her third heat at 2 years old. I will say for a long time I was worried she might not make standard but she did. Give her time she can still grow.

I also have girls that definitely grew after their 2nd or 3rd heat.

It is true when we are worried and watch them grow they either keep looking bigger or look like they are not growing at all. It depends on which side you are on the getting to big side or the not getting big enough side.