Including related data in restful results

I am trying to create a restful XML output for a model but also want
to include the data from a related table. For example, I have a model
called person and the person has multiple photos. I want to include
the url of each photo so that the restful user can then retrieve the
photos if needed. I know I could create a separate url like person/
123/photos and that would work, but is an additional query. Either
would include a url of the actual photo photo/987. Again I could also
do person/123/photo/987

Would I be better off to have the one url of person/123 return the
person info along with the photos or separate urls as mentioned above?
Also the pros and cons of the extended photo url

Don French