It would be helpful to us if you could send us a photo or two of the whole tree and the arrangement of leaves along a branch, which would give us more clues as to what species of tree it is. In turn, we'd have a better idea of what could be affecting it.

More photos can be attached directly to this reply.

Thanks.

Christine

We don't think that your neighbor needs to worry or take any action for her tree.

While there looks to be some minor leaf spotting, we are seeing leaf yellowing and fall across multiple species that is related to them producing many more than they need in the spring, and then dropping some as we have entered into a period of a rain deficit (about 2" below normal right now) and unusually high heat for May.

Unrelated but interesting, we think we see the leaves of two different types of trees. The large tree looks like it could be a Boxelder (which is a type of native maple) and the small outgrowth to the right with heart-shaped leaves could be our native redbud or something similar. We wonder if as the boxelder grew if it encompassed this smaller tree.

Christine