Well, if Xavier ever had a sidekick it was his ex fiancee, fellow researcher and Muir Island occupior Moira. I'd been toying with the idea of making her for some time and the sidekicks contest got me into gear to do her. She is all Wasp with trimmed FF4 Movie Invisible Woman hair. The sleeves, fringe and headband are apoxie sculpt and the glasses are picture wire. The coat is a Hulk Classics Bruce Banner jacket so not too much painting required. I've no idea where the writers got the idea for this outfit - we only assume they'd been to see the Rocky Horror Picture Show the saturday before hand :) (pink boots and a lab coat... hmmmm...)
Here's a little background on her:

Moira met Charles Xavier in Oxford, and the two fell in love. However, when Xavier went to the army Moira didn't wait for him, and eventually married Joe MacTaggert. When Charles returned to the United States, however, Moira had apparently separated from Joe, and she opened a research clinic in Westchester, not far from the X-Mansion. Together with Xavier and Karl Lykos, they researched the mutant phenomenon. After Lykos left and Xavier formed the X-Men

Moira next appeared as the Mansion's "housekeeper" (never mind that she packed an M-16 like Rambo). In reality, though, she was a brilliant bio-geneticist, and one of the world's foremost experts on mutations. She spoke from personal experience: Her only son Kevin was the mutant named Proteus. Moira spent all of her time trying to find a way to control his energy-warping and -draining powers. After her ex-husband Joe was killed by Kevin, the X-Men were forced to destroy him. Moira ran the Muir Island Genetic Research Station and was for years the love of Sean Cassidy, AKA Banshee. She was also the first and only human to contract the Legacy Virus, and was constantly working on a cure until Muir Island was destroyed in a bomb planted by Mystique and her new Brotherhood. Moira was gravely injured, but Mystique's manipulations of the virus to make it affect humans clued Moira into the cure for the epidemic. Knowing that she had to get the cure to someone who could use it properly, she hung on (with the help of the X-Men) until she was within range of Xavier's telepathy. Xavier's astral form took the cure from Moira, but was unwilling to let her die, though her death threatened to kill him too. Finally Xavier was separated from Moira by Phoenix IV and Cable, and Moira succumbed to her injuries and died