DP and I are self-employed and work from home, so she is able to be with us FAR more than most kids I know. But we do need some work time each week -- keeping her home with us is not an option.
At first we were blaming the summer camp (and I do think there were some problems there) or a specific babysitter we tried this summer, who she just didn't seem to hit it off with. Maybe those things triggered this upsurge in separation anxiety. But now it happens everywhere, every time we need to drop her off, regardless of which parent it is. She says she doesn't want to go to the given place, and cries hard when we leave. The various caretakers say it lasts 30 seconds to 3 minutes (I've hidden out of her sight where I could still hear, and can verify that time range), and then she's fine. She's happy and bubbly at pickup, not even in a rush to leave.
I feel like we're entering our 4th month of this, and I'm not seeing any change, except the feeling that now she's in a rut that "this is how we do it." She will turn 4 in 3 months. The only separations now are preschool (again, very familiar, teachers are beloved to her) and the 3 year old neighbor whose mom she adores. No more summer camp or babysitter who she says she didn't like.
We have been "practicing" preschool dropoff at home, which she loves to do (sometimes she plays the role of the mom, sometimes she plays the role of the kid). We talk about how she's sad at first but then she has fun, and she agrees that's true -- even she can predict this when we talk about it. She just doesn't like the moment of being left (even if someone is engaging her in an activity), and she clearly feels a lot of anxiety about it -- it's what she's thinking about it in bed the night before.
We've also done lots of reassurance about parents always coming back (that doesn't seem to be her worry), about the people who are there to take care of her, about the fun stuff she will do while she's there. The book The Kissing Hand, which helped her a lot last year, doesn't seem to do the trick anymore.
What else can we do to try to get through this? I wish we could pull her out of everything and keep her home for a few months, but it's just not an option. It still breaks my heart to leave a wailing, sad kid.