Different time control

Hello.

I want to play with my friend, but I am much better then she is, so I would like to have less time (lets say i would like to have 2 minutes and she 10 minutes).

How is it possible? (Or is it?...)

Neviem, musí tá baba viacej hrať, či?

lel  Peťo, kedy zahráme?

I am also interested in the same topic. 
We have a club and some IM are attending some tournaments. 
One idea would be to have something like 5+2 for regular player (<2300) and 2+2 for above 2300 rating.

I asked people in my clubs and they told me that this is not possible to set. 

Stating the obvious, I'm sure, but you could do it artificially by prearranging the late start of the player being short-timed.

This is not available on chess.com yet to my knowledge, but as @krylenko mentioned: there are ways of artificially setting this up. If you set the game to unrated, you have an option to "add time" to the opponent in intervals of 15 seconds. You can either intentionally let your clock run longer between moves to lower your own time or simply add time to the opponent (probably easiest).