Was friend somebody since college. We were roommates for a couple of yr in college. Super close even years later when we both had kids and lived in the same metro area. We'd meet up a lot, support each other, all of the good things you'd want in a friendship.
It was great...until it wasn't. When my kids were 5 and 7, Spouse & I opted to enroll our kids in a charter school. Friend took it personally, like I had betrayed her or something. Ironically, my kids never would have attended the same school as Friend's kids anyway because of where we lived. Friend also got super upset & offended when I opted to not enroll my kids in a 2nd yr of dance lessons (Friend's 2 daughters were super duper into dance, to the point where she spent about $400+/mo at the time on lessons). I switched my kids to do swimming instead. They liked it better.
Friend was mad. She started getting really into hanging out with other dance moms. Suddenly started doing her hair differently, dressing differently in an attempt to fit in with them. She started acting like them, too...snarky, rude, passive aggressive, putting people down. Not very nice.
For a long time, we'd get together at her house every Halloween to take our kids trick or treating together. That year that my kids were 5 & 7, she made plans to go out instead with a dance mom, but she didn't tell me ahead of time. She ditched me.
But due to our long-standing friendship, I excused it in my head and kept trying. Our monthly mom's night out dinners became less frequent. She stopped calling me back as often. And then she just stopped calling me back altogether. One time, she & I were out to dinner and a different friend of ours came up to our table and invited her to meet up later for drinks. Friend made plans to do that right in front of me and I was not invited.
Rude.
Friend also started talking trash to me directly, saying that my kids would "flunk out of that school by 5th grade and then you'll be back in regular public school again and I'll laugh at you and say I told you so." Guess what? My YDD is graduating from that charter school this academic year and has done really well. So Former Friend can go suck an egg.
So yeah, back when YDD was 5 was when the friendship died. 12 years ago because YDD is now 17. I mourned the friendship for a really long time. But some friendships only last for a season or 2 of your life. Not all friendships are meant to be forever. It was great while it lasted. ...until it wasn't great anymore. It was toxic. She was toxic.
2 yr ago right after her youngest kid graduated from high school, she filed for divorce and left the country. Basically, walked away from her entire family. Her eldest kid got married. Friend wasn't there for that. Her youngest kid started college...she totally missed that, too.
In my situation, I never told Former Friend why I disengaged and why I ghosted her (I unfriended her on Facebook & blocked her). There wasn't any point in explaining myself because through her behavior and what she'd said to me, it was obvious that she didn't like me anymore and didn't really want to remain friends. And she had become so snide, snarky, rude, and negative that, to be honest, I thought that she'd become a total "insert your favorite swear word here." She was NOT somebody who I wanted to waste my time with anymore.
When I decided that I was done, I finally realized that the only reason the friendship had continued for the last 2 yr that it did was because I was trying so hard. I was the one keeping it afloat.
So I stopped trying. And when I stopped trying, everything disintegrated and disappeared.
I'm glad now that the friendship ended. Its time had come to an end. It just took me awhile to realize that.
If you DO decide to explain yourself to your friend, you should not expect it to go well. If you do decide to proceed with that, only do it for yourself...not because you hope or expect your friend to turn it around and apologize and promise to make amends with you. It will not go like that.
If there are other people involved in this on the outskirts (you mentioned family friend, for example), you SHOULD expect your friend to talk smack about you to everybody else, twist your words, retell the tale in such a way where your friend appears to be the victim. You should expect some of those people to come back to you like flying monkeys and they will try to convince you to make nice with your friend in order to keep the peace.
...that's why my advice to you is to let the friendship quietly wither away and die on its own. There doesn't have to be a big finale send-off.
