I let them watch most programs, my oldest four are 11, 9, 8 and 6.
look through the menu together to see what's available and what she finds interesting and watch those things together so you can both decide. there really is a wide variety from junior master chef (love!) to scooby doo (eh..) to sit-com types (ok)
She's still only five so after the very youngest end of CBBC, if appropriate. she's seen My Monsters and Me which she loves but I think some of the themes are a bit old. Today she watched Dennis and Gnasher...
I think that what I've seen so far there's nothing inappropriate so to speak, but yes some things are better for when she's a little old
the only ones I don't like are ghost and monster stuff, but the funny thing is my 8 year old will run away but my 6 year old (well 6 next month) loves scary things, he's favourite film is Jaws! (he saw it by accident, he was ill, and sleeping on the sofa, I watched the film on almost mute, then halfway through I realized he was watching it too...)