If I word this correctly, there should be something in this response to offend everyone.
1) I'm not an expert on this, I thought that redosing greatly increases the risk of toxicity. You should check that out. (For myself I don't need to know for sure whether that's true, because I don't redose.) If that is true about redosing, and you have any love for this person, you should not have her redose.
2) For myself, I found titrating mdma to be pretty tricky. For me I found that there is a *very* narrow range of milligrams that works well for me. But, I went to the effort of securing a fairly large amount of a single batch of known mdma so I knew I was always dealing with the same potency substance. Also, I took some time in advance to think this through and define for myself what "works well" means. I decided I wasn't going to get obsessed with chasing the "perfect" roll, I decided I was quite happy with a really good roll.
3) What does *she* want? How aware is she of the issues involved? I'm assuming you're not doing this just for your own giggles. (I hope not.)
4) Some people in previous postings seemed to be saying that going up to 150 mg - or even more? - should likely be alright. I don't know about that. I'd go with what futura said in posting #4 above (especially since his reported experience with mdma is pretty extensive, I don't know how the experience of the other posters stacks up against his experience). Here: I'm a man, 170 pounds (don't know how many stones that is for you UKers

). If I go over 120 mg, I have great, great difficulty remembering much of what happened. Well, wouldn't that be epic for her: "Yeah, I really don't know whether I gained anything from taking mdma - I can't recall anything about the experience." I understand we're all a little different in terms of sensitivities to doses, which is why I recommend you do what futura advised. She'll likely enjoy it a lot, and will certainly remember it. Otherwise, if she can't remember much of it, it won't be much of a shared experience you two will be able to jointly enjoy recalling in the future, will it?
5) I feel I must say this. I don't know how old you two are, but if you're really young, something crazy like only 16, you guys shouldn't be doing this at all. You're too young, you ought to focus on how to grow into young adults first. And.... If you're in your 40s, ignore what I just wrote. Sorry to get preachy.
6) Ok, I thought about it a little more, the truth is I'm not sorry that I got preachy.