How about something personalized? I was trying to find the perfect gift for my niece a few weeks ago, and I decided on some custom-made toys. She loved seeing her name engraved on some of her favorite characters. You could also look into these unique couple gifts https://giftedstories.com/collections/custom-couple-mini-blocks which can easily be gifted to a kid, as well. They're like a little representation of a person captured in blocks. I think the kids would love something like this.

At her last bday my 7 year old was really excited about a Fluffie Stuffiez. I think she’d still be excited at 8.

Binoculars or a plant potting kit, if she’s into hiking and nature.

Tickets to a kid’s show if she’s into performing arts (two tickets to go with an adult).

Passport holder if she travels internationally often.

Books, puzzles, mankal

My niece just turned 8. I got her a heart-shaped purse that she really likes and now uses all the time.

https://www.amazon.com/gp/product/B0B6GY4MYP/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

OP here. Thank you for all the ideas. I will pick now something to buy!

Same advice as the above- craft kits. My daughter picks her friends' gifts and she almost always gets the kit. Usually asks to add a Squishmallow.

Pony with styling accessories

My 2nd grade girl loves Lego friends, arts and crafts supplies, and any kind of “making” kit - wool felting, crochet, hot cocoa bombs etc have all been hits lately.

Face painting kit was recently a big hit with my 8-year-old.

Squishmallows

Art kits from Target or Perler beads.

I have an 8-year old that likes artistic and crafty things such as:
diamond painting
rock painting
jewelry making sets (beads or string for bracelets)
spiral art/spin art

You can find most of those in Target down the art aisle near the school supplies.

She also loves squishmallows and lego sets.

Lego Friends, arts and crafts kits, graphic novels, Magic Mixies, Miniverse.

Stationary/gel pens, Barbies, modeling clay, jewelry kits

My daughter has a couple of birthday invitations coming up soon. I'm running out of ideas what to buy for 8 year old girls. Can you give some links or ideas what to buy? Or for you who recently had birthday parties and liked certain gifts for 8 year old girl? Price range $20-40 per girl.