Blackberries are ripe all over western WA this time of year, so that's probably what she was eating.

From what I understand, all aggregate berries (tight clustered fruits, like blackberries, raspberries, etc) are edible.

The single fruits, like blueberries and black nightshade are much more iffy.

And don't judge toxicity by seeing birds eating certain berries. Deadly nightshade (Atropa belladona) is one of the most toxic plants of the western hemisphere, but birds can eat them with no harm.

Sue