“I stammered. I have never beheld anyone as purely lovable as Mona, and I never would, I was totally aware of that. The world hung by a thread, and I had to seize the world and snap the thread. ‘Mona, come away with me.’”
These two become lovers in Blackwood Farm when they are both mortals. I think they are good for each other even though I love Quinn and find Mona quite irritating. Mona is getting over having a Taltos child who deserted her and feels quite alone in her house with Michael and Rowan and Quinn is a refreshing change from her normal life since she doesn’t tell him right away what’s wrong with her (she is deathly ill from having too many miscarriages).
“Don’t worry, my brave Ophelia… you shall not perish while this brave Laertes lives.”
They are lovers until her condition worsens and until Quinn goes away to Europe for four years and ends up a vampire. Then Mona comes to his door from her deathbed and Lestat makes her a vampire. That is another reason why their relationship makes sense because those who are not fledgling and maker tend to get along better and not resent each other eventually and are not bound to each other necessarily.