Most of the boys will accept them eventually! 
Scouts Canada has been co-ed since 1998 from Beavers all the way to Rovers. There you go, a 20 year experiment - go find some evidence of your deep misgivings.
At least in the small town in southern NJ where my wife grew up, the Girl Scouts were an invitation-only social club and Jews were rarely, if ever, invited. We would not be unhappy to see the Girl Scouts get their comeuppance.
On the other hand, the Girl Guides here in Canada were a wonderful experience for my daughter. One thing I remember they did was winter camping in which they slept in an ice house, a kind of igloo I guess. Although she commented that now that she had done it, she wouldn’t have to do it again.
I was talking to a Girl Scout leader yesterday in PT. She is aghast that this is happening. It’s not so much fear of losing her troop/position as it is that she firmly believes boys should have their thing and girls should have theirs. “If it isn’t broke, then why fix it?” she said.
I pointed out the whole “Boy Scouts tend to do the more exciting outdoor things” and that, even though I was in Girl Scouts all the way through Cadettes, it didn’t seem my outdoor experience was the same. I’d earned a bunch of outdoor-type merit badges from going to camp every summer, but if you asked me, say, could I shoot a bow and arrow? Could I rock climb? Get purposely lost and find my way back using a compass and rudimentary survival skills? Nope, nope, and nope. The Boy Scouts taught all that.
I have no idea how the Girl Scouts are nowadays. I do know, though, that they’ve had to either disband or merge councils in my area because the enrollment dropped.
Was it a quinzhee perhaps? My sons, in their coed troop, did the same thing and had basically the same reaction as your daughter. They did go again in future winters but it took a summer to warm back up to the idea. 
[quote=“aceplace57, post:35, topic:798590”]
(snip)Teen pregnancy rates have been steadily dropping for many years. I hope making Scouting coed doesn’t change that trend.(snip)/QUOTE]
I wouldn’t worry about it much. That Boy Scout uniform is still the best female repellent ever worn.
In fact, the Venturers (14-17 years old) have been co-ed since the 80s, and the Rovers (18+) since the 70s.
Giving it some more thought, I think it’s worth emphasizing that the Venturers and Rovers are in the Prime Indiscriminate Fucking period, whereas Scouts are generally barely out of the Girls Got Cooties phase.
The picture in your link is pretty much the way she described it. It was interesting once, but she didn’t want to repeat it.
My nieces have tried for years to get any of the local Girl Scout groups to be interested in ANYTHING other than junior coffee klach and flogging those damned cookies (yes they’re still tasty and yes I still buy them, but the stories they and their mom tells about the pressure on these girls and their families to rake in the cash is just depressing as shit.) They’ve had zero luck finding anyone else in Girl Scouts in three counties who wants to be more adventurous or active.
They’re over the fucking moon about this. They can’t wait to go on a scout camping trip just like their dads and uncles did.