My girlfriend received her 45-days schengenvisa in october so we could go on holiday in Europe. I need to go back for medical treatment and my gf would like to come with me. Is there something like a waiting time to apply for a second schengen visa?

She can't stay longer then 90 days within a 6 Month period, you can do the math yourself.

The Schengen visa allows the holder to a total stay of up to 90 days within a period of 6 months for tourist or business purposes. If you get a multiple entry Schengen visa, you may leave and return any number of times within the 180-day period, but the combined stay within the region must not total more than 90 days.

http://www.immihelp.com/visas/schengenvisa/

She received a Schengen visa valid for 45 days early October which we used for a 3 weeks holiday. That visa has now expired.

So that means she can apply for a new Schengen visa?

 

She received a Schengen visa valid for 45 days early October which we used for a 3 weeks holiday. That visa has now expired.

So that means she can apply for a new Schengen visa?

Yes she can, best to explain in a covering letter why she's applying for another visa so soon, just to avoid any doubt.

27 days out of 45 is how a tourist visa should be used.

You'll have no problem.

Good luck

27 days out of 45 is how a tourist visa should be used.

You'll have no problem.

Good luck

Can you explain that ?

VFS just got back to me and you guys are right. No problem at all.

27 days out of 45 is how a tourist visa should be used.

You'll have no problem.

Good luck

Can you explain that ?

Have you put this in the "too difficult" box ?

If you are going to make statements, then be prepared to back them up, not just ignore people who question your knowledge, yet again.