I'm pretty new to this site having just discovered it and posted my 13 week scan images of twins for guesses. I don't feel very qualified to answer your questions but am offering my thoughts. I have 3 boys, much more spread out than yours - 11, 8 and 4.5. At the age of 39 I assumed we'd completed our family and that was that. But we moved to France a few years ago and having a 'final' child became a possible option with more space, different work patterns etc. and we decided to give it a go. I rather half-heartedly tried to influence the 'girl' aspect but probably didn't understand all the ways to do this so just did the more basic things which seemed possible! Then I found myself pregnant, and later found out with twins. Double chance of a girl?! Or a 5 a side football team of boys?!
I've found, at just 14 weeks, that other people are more obsessed as to what I'm having than I am. It seems to be the first question followed by the 'oh, imagine 5 boys'. Perhaps the bonus of twins is that they're just a little more out of the ordinary so if I have 2 more boys, they'll always be 'twins' and something a bit different.
So when I posted my pics (and learnt all this 'nub' terminology) and the verdict so far was that they were both girly pics, I'd be lying if I didn't say I wasn't excited/intrigued. HOWEVER, they could be boys! And I think that this just brings me to emphasise that I fully understood the chances were big that I'd have another boy when I fell pregnant, and that I was OK with this. If I wasn't going to be OK, I probably would have thought longer about it. Time wasn't really on my side so we went for it. Although I have a good relationship with my mum, I also look at my husband who has a great relationship with his mum and speaks to her far more than I do with my mum. Mums and boys, as they grow up, have a really strong bond. Yes, I fully understand about your mother-daughter dream but sometimes my girlfriends remind me how tricky their daughters are! I don't mean to belittle any of what you say because I think I understand it and I have a friend of a friend who suffered tremendous GD which lead to many longer-term issues for her. But if I was you, and I thought I did want to try one last time, I think that I'd take your time, look at all of the advice which people give on here to 'sway' things, chart your dates for a few months to understand your body (this was one thing that I did do) and think of it like this - you are going to give yourself every possible chance possible to conceive a little girl, using all the methods you know. BUT if it doesn't happen and you have a boy, he will be the final jigsaw in your family puzzle and you will be blessed to have 4 children. If you think that you can honestly get to this point, then I would be inclined to have a go so that you at least try and put your mind at rest. Obviously 4 children is a lot of work and yours are quite young, but if you are at this stage of nappies and sleep training etc now then you are pretty used to it! You sound a good mum to be so honest about your dilemna and are obviously keen to not make rash decisions. Be proud to have your 3 boys, and possibly 4 boys one day. And who knows, maybe one day a mum of a girl too. I haven't read any of your other postings so if I've missed the point of your message I'm sorry, I was just browsing on here and saw your posting and decided to respond. Best wishes.