Writing an update to foster parent, how much info do you give?

I want to send Tucker's previous foster mom an update on him since we've had him four years today (happy gotcha day Tucker!). She whelped him and had him until he was ten weeks old. I've written updates on the rescue's facebook page before but have no idea if she goes on facebook so it's possible she hasn't heard anything about him since a few days after we got him. I wrote up a nice update and am going to send pictures. I'm debating on whether to mention any of the negatives. I wrote all positive stuff so far, but obviously Tucker is stranger aggressive and dog reactive and it is an issue. We love him and will never get rid of him over it, but it's a large part of who he is and brings daily struggles. What do you guys think, keep it all positive or let her know some of the issues we're having? My gut says to keep out the aggression stuff, but I sort of feel like I'm lying.

I would include it, even if briefly, but put a positive spin on it because clearly you love Tucker. You can absolutely be transparent and honest without making anything sound like you are a bad owner, Tucker is a bad dog, or she was a bad foster parent. As a foster parent, I am sure she doesn't have blinders on when it comes to reactivity and aggression.

I'd just say something along the lines of "We've had our fair share of struggles. Tucker still isn't much of a fan of strangers and can be quite reactive, but we have been consistently working with him and he has opened our eyes to dog body language and behavior. He will most likely not ever be a "go anywhere" type of dog, but we love him dearly, and with the family, he's a joy."

Of course, I don't know if everything that I said above is true of Tucker, but you get the gist. Honesty said positively

I probably wouldn't include it, not because it's wrong, that's just.... me. When I send Juno's breeder updates, I don't mention her anxiety and that she's on Prozac - it's a part of who she is but it's not all she is, she's awesome in 1000 other ways and I'd rather focus on and babble about that. There is also a part of me that feels like no matter how I word it, too, that it'd come across like I'm faulting her for that - which I don't.

This. This is what I do with updates on Tipper. "She's doing this and this and <funny story> and we still keep her and Mu separated but I can't imagine life without her." If Tucker's foster mom is anything like Tipper's she will just be incredibly grateful that you love him and will keep him forever.

This.
Don't focus on the less happy stuff, but I think it's good to mention it.

Especially if these are things that might have benefited from extra socialization as a young pup - maybe it could be helpful for her to know if she fosters another litter?

I'm sure she will be happy for the update either way

This.

If there is anything constructive that can come from providing the downside details then include it. Otherwise, there isn't any benefit from airing the dirty laundry IMO.

-Mark.