Tween ? patterns

[Syrinx]

Task has arrived - a few pieces for a cousin who looovvvveees clothes but is tall and can no longer find the lovely cute dresses and tops she adores. So I need to find some to make for her for christmas. I'm waiting on her actual measurements but she's apparently fitting into age 11 already!

She loves girly stuff and I'm sure I can find a tonne of cute cottons and jerseys to make said stuff out of but I can't work out what search terms to pop into google and etsy. I've found a couple of dresses but the sizing seems to stop too young or they are designed for 16 year olds.

As I'm not someone who makes kids stuff I am unsure how hard it is to upsize the ones that stop age 9/10 - is it doable with just measurements and no fittings?

Also any ideas on patterns or search terms would be great. "Everyday pretty" I think is what we're aiming for, so no party dresses. I don't have an overlocker so think pretty leggings may be out of my current skillset with jersey too.

Hunting out hoodie patterns so think I'm good on those.

Also if anyone knows any good boys stuff (bit younger) that would be cool, though I may just go with hoodies with dino applique or maybe marvel fabric!

[UttaRetch]

I searched for 'tween sewing patterns' and looked at the images.

[wrenkins]

A lot will depend on the fabric you choose. Some of those patterns suggested by @UttaRetch look perfect but shop wisely for your fabric. 

[PollyWally]

I follow this blog  Thornberry - Children's Clothing  You might find some inspiration there.

[dolcevita]

October Design have fantastic p patterns for children, from toddlers to teens, in their Ottobre Kids magazines. It's worth a look now as they offer free shipping at the moment and you can also order back issues.
Tracing might be new to you but it does have the advantage of making it easy to grade between sizes.
Here's the Ottobre website:

https://www.ottobredesign.com/en/

[jintie]

I just use a narrow zigzag on leggings. The fabric doesn't usually fray.

[Catllar]

Love Notions Patterns have sizing that covers that age and they have hoodies! You don't need an overlocker provided you have a zig-zag as @jintie  said.

[UttaRetch]

Jalie patterns go from children to adults and include leisure and 'performance' wear.

[Lachica]

Look at Ellie and Mac, Brindille & Twig, Made by Jack's Mum, (Beachcomber gets lots of good reviews) Life Sew Savory. There are lots of others -ive used a free DIBY Club t shirt, it's well draughted. These tend to go from 6 months to 14 or so, simple designs ideal for stretch fabric. Some are free, some on sale for $1and some are around £10.