One of my FC members is new to dealing with materia and melded an extra crit materia on her Vanya hat without realizing that it was giving her +0. Thankfully she came to me for her forbidden melds and I caught it. Anyway, she apparently cannot get the option from Mutamix Bubblypots to remove Materia and from what it sounds like, that option is blocked until you get a level 19 crafter and do the initial melding quest.

Is this the case, or are we just mistaken and there is some other requirement she is missing?

If this is the case, can this be changed? 19 in a craft doesn't take very long but it is an unnecessary requirement to remove materia when you don't have to get 19 in a craft to request others to meld for you. I'd imagine it's also fairly confusing to new players if they hear about materia removal as an option and can't access it.