If they are both Telepaths how would Emma melt her brain when Psylocke can do the same?

Psylocke doesnt have to get close to you to 'melt' your brain.
She just enjoys the thrill of close quarter combat,as she has stated already.
That's why she loves using her energy blades.
So if they were fighting it would be down to who can fight the best,and even if Emma does go diamond form she still cant beat Psylocke in hand to hand combat.
After all Psylocke has BEATEN Wolverine in hand to hand combat.