Mike
D.I.Y
The majority on here never used a Agency and were approved for a visa.
I doubt the british embassy in phill would think oh its an application sent with the help of an agent, we had better not interview them.
In fact from writing i have seen on the website of the embassy, they actually warn people not to use agents or fixxers.
Follow the basic proceduere mentioned all over this forum and you both should have no problem.