Speed workout? Not really sure what you mean. Yes, samples would help. Thank you. If you don't mind my asking, how are your PFE scores like right now? It sounds like you're on the right track!
Right now I'm managing just a 200. If she has access to a track and only runs shorter distances I suggest doing something along the lines of:
1x 1200 (3 times around) then 2x 1000 (2.5 times around) then 3x 800 (2 times around) timing these will help keep progress and build speed.
For longer running my 2 favorites are 3.5 miles:
1/2 mile easy pace, mile harder (but not so fast she's dead after), 1/2 mile easy, mile hard, and half mile easy.
Or another that's just 2.5 miles (the 'just' might sound crazy, I run cross country): 1/2 mile easy, 1/2 mile sprint-jogs (if she's on a road 1 block easy, 1 block sprinting), 1/2 mile easy, 1/2 mile tempo (gradually getting faster), and 1/2 mile easy.
Make sure not to do these EVERY day, just if she's running say 5 days a week, throw one in once or twice.
Hope this helps!