Anyway, the point is, in my nextgen, they're all given someone to teach them about friendship. Luna volunteers for Chrysalis, because she feels a connection; Chrysalis also tried to earn the love of her subjects the wrong way. In the process, they fall in love.
Fun facts:
-Chrysalis used to be a few inches taller than Celestia, but upon reforming, she actually shrunk a little. Despite being even shorter than Chrysalis, Luna loves to call her shorty
-Thorax was very excited to have Chrysalis back, but she feels a little awkward around him, and all her old subjects. He offered her her throne back, but she refused, insisting he was doing a better job anyway
-After a while, Chrysalis gains a bit of her confidence back, and makes jokes about how overinflated her ego used to be
-They officially adopt Cozy Glow shortly after being married, but travel the world for a few months before settling down and having more kids (whose designs are probably up next). They build their own house in the Everfree forest, between Ponyville and the Changeling Hive. They take their family on trips and vacations often
-Celestia and Luna exchanged friendship necklaces that they each keep on them always (it might change design though XD)
-With Luna being a retired princess, they don't really need to worry about income, but they're both too bored without something to do. Luna tends to a garden of nocturnal plants, and continues helping ponies with nightmares, though not quite as much as before. Chrysalis has her own section of the garden where she grows carnivorous or otherwise "ugly" plants. She also becomes somewhat of an entomologist, keeping pet bugs around the house and in the garden greenhouse. She's consulted when new species are discovered, when museums across Equestria want to add live insect exhibits, and sometimes when a town gets an infestation. Luna doesn't always love this, but she tries to encourage her wife's passions