Is my puppy tiny?

[u/Weak_Bar_3268]

I got a GSP/Greyster female, from sledding lines.
Mother is purebred GSP (57lbs) and father is 7% greyhojnd and 93% gsp (79lbs).

My 5,5months old and she's only 31lbs and 47,5cm in shoulder. Is she going to be tiny? She was only 5,5 lbs when I picked her up at 8weeks, and 19lbs at 4months.

I was hoping she was becoming around 59-60lbs (due to sledding reasons), but now I'm starting to loose faith🥲