[DianaM]

She has a very malinois-like build. In other words, I'm sure she's one agile and quick little cookie.

http://www.pedigreedatabase.com/dogs/belgian_malinois/pedigree/495875.html
Case in point, but Ris looks more square,

http://www.cck9.com/dutch/index.8.jpg
Or a very dutch-shepherdy build. In any case, as stated, I'm sure she'll have no agility problems. Have you tried biking with her and noticed the speed at which she shifts from a trot to a gallop?

http://www.shawlein.com/The_Standard/11_Movement_3/Movement_3.html
From what I interpret here about the flying trot and balanced angulation, a dog with good, balanced angulation, front and rear, will maintain a flying trot at higher speeds before switching to a gallop. A dog that is poorly angulated or unbalanced will switch into a gallop at lower speeds. If Ris can maintain a flying trot at high speeds, then she's correctly balanced and angulated for her body.

Do her withers look a little flat or is it just me?

 

[DianaM]

Yes, she sure does look like she has the sighthound double suspension gallop. There's your answer there- whatever she is, she is part-sighthound. That last photo looks a lot like a greyhound face.