3 students per class

Hi everyone,
Today I have received a message by a student asking me if I take classes for 3 students at the same time.
I am considering saying yes but raising the price a bit than my normal rate.
My doubt is that Preply doesn’t encourage changing your rate before the 90 days timeline.
Considering that they haven’t booked yet the trial class, if I raise my rate, is it considered as a raise before the 90 days timeline?

Thanks for the help