Why would you use your parents doves? Do they know your gonna be using them for a spell? Another thing, how advanced are you in magick, how long have you practiced?
You really shouldn't cast a spell just because you have the means to do so. You should cast a spell when you need to solve something using magickal means.
I know of an old English love spell that involves killing the dove by piercing it's heart with a pin, then filling it with herbs and saying enchantments. Although that would go against free will, if your Wiccan. And I don't think that's what your trying to do anyway! ;D
I agree with the previous post though, they are good for driving way negativity. When your using them though, I wouldn't keep them in a cage, I would hold them, let the needy flow better.