How old is she now?
I'd go back to socialization 101... introduce 1 new object a day, 1 new location a week and if you can find 1 new human a week, that would be a bonus, too.
Objects: Flags, umbrellas, kids toys (things that move, make noise, etc), vacuum, cars, culverts, ladders, wheelbarrows, etc.
Locations: New trail, new neighborhood, new park, any place you can reach in a reasonable distance... just taking your coffee to sit quietly together in front of the local grocery store for a bit would be great... but might be a bit down the road from a training perspective.
Baseball season is starting up... are there any kids leagues in the area? Go visit a game - from a "safe" distance, slowly working in closer over a few months time until you can sit with her in the stands with the other parents.
How about school yards? walk around the school when kids are NOT there first... then during recess - from a safe distance - work her up to her "alert" distance, have her sit and supervise the activity from there for a while... treat, and go home. Work closer each day, but still just to the "alert" distance, retreat if she gets too nervous and try again.
Do you have any neighbors with (or without) dogs that you can arrange Meet & Greets with?
We have a "nextdoor" web page for our community (and a facebook group) - putting out a request for Meet & Greets to help with dog training gets LOTS of positive responses in our area (and a few idiots, but... that's to be expected in a city suburb).
Teaching tricks is another good way to reinforce your dog-human bond and teach her confidence. Get high value treats and a good book on dog tricks, and go for it! Keep it fun and always ALWAYS end sessions with something she knows how to do well and can be handsomely rewarded for.