Tethers I think you've spoken very well on this thread.
I have a boy, after previously losing a boy and then a girl within the space of eleven months.
In all three pregnancies I admit I had a bias towards wanting a girl. We didn't find out the sex at any of the scans because I worried that I would be disappointed at a scan but elated at the birth (if that makes sense).
In the first pregnancy, I wanted a girl because I have no real experience of baby boys, my friends with children all had girls at the time, and I was just a bit worried that I wouldn't know how to be a proper mum to a boy.
When we were told at the scan that the baby had died and that I would be induced two days later, none of those worries mattered. I just wanted the back. At that moment, they couldn't even tell us if he was a boy or a girl because of the position he was in, we had to wait for his birth and oddly, once he was born and we knew, in the middle off all the grief and pain I managed to feel embarrassed and ashamed at having wanted a girl and blamed myself a bit for making him feel he wasn't wanted.
In my second pregnancy I still hoped for a girl, this time because I was scared our son would feel he was being 'replaced' in some way, and I thought a girl would be less upsetting to him. Not rational at all, but still very real feelings. When she was born prematurely it was a relief to know she was a girl even though we also knew she would die very soon after her birth.
And in my third pregnancy I felt the same small bias towards having a girl, this time I think because we had seen and held our daughter but we hadn't been allowed to see or hold our son. So I felt that I had time with her to let her know I loved her and that I wasn't replacing her
And when LO turned out to be a boy it did come as a bit of a surprise (even though the woman who did our last scan gave the game away to me by looking when she said she wouldn't) to have a boy. During the labour I'd become so ill and confused I had somehow convinced myself I was back giving birth to my daughter and it took a few days for me to come out of that and realise that my baby was not a girl and was not about to die. I think we'd been home for over a week before that sank in.
And I wouldn't be without him now, wouldn't swap him for a girl or change him in any way.
What I do find hard is knowing that I won't ever have a mother-daughter relationship, even though I feel privileged to have a mother-son one.
All my pregnancies have been hard, more than once they could have killed me. I'm not brave enough to risk another loss and I'm not getting any younger. I am fairly certain we won't try again and if we did there are no guarantees of having a girl.
Although I can say with honesty than now I have my son, if I went on and had a football team of boys and no girl I would welcome them all.
It's great being the mother of a boy, I love it in ways I can't even describe.
But it does still hurt, knowing I won't have a living girl. And it's not about the weddings and pink frills, that was never my style anyway (and I doubt it's really your friend's either OP). The wedding is more than likely a metaphor for the bond she wanted with a daughter.
So I think what the others have said is right, you can be gentle with her feelings without indulging them.
I doubt she wants to feel this way and is probably feeling like a terrible person even though she can't help it.
I feel sorry for her and I think she's lucky to have a good friend who cares and wants to help.