When Cute Charm is triggered in Gen 4, it chooses one of 25 predetermined personality I'd values (one for each nature) that it forces the wild Pokemon to have, and if your trainer I'd is a specific value, up to 8 of those 25 forced pid values can be shiny. If you have the Cute Charm Glitch on your file, then yes, all shiny Pokemon caused by the glitch will be the opposite gender of your Cute Charm Pokemon.
Shiny Pokemon of the same gender are still possible, but only if the Cute Charm check fails. The chance of finding a shiny that is not caused by the glitch while it's active is 1/24,576 (and that's before taking the species' gender ratio into consideration).
Source
