Discussing finances with advisor: Am I being selfish?

I have a bit of a quandary. I applied for a fellowship to send me to a foreign country for two months. They will give me a stipend, and pay for all of my other expenses. In the event I don't receive this fellowship, my advisor said she would fund me the whole summer using her discretionary funds. I would go on this trip and make it back exactly one month before classes start: would it be selfish for me, in the event I get this fellowship, to ask her to also fund me for that last month while I'm back and doing work?

The thing is, the fellowship stipend is about as much as I would make during the whole summer working here, so I would be making more money than I would normally make over the entire summer. Perhaps I am overthinking this.