Your albino was was produced by inbreeding. It is how oddball traits are reproduced when they are first found; thus all compatable albino's are somewhat related. This is why Sharp and Kahl albino's are not compatable. They are two different genetic mutations; both causing albinism, but reproduced in two different family trees.
With all this said, it is a good idea to bring in "out-stock" to breeding projects to widen the genetic diversity. So while you could have bred your snake with it's sister, it is not a bad thing to have passed on that opportunity. Breed your snake with a normal BCI to produce 100% heterozygous offspring. Then by inbreeding once, with these het's to the albino father, you will produce some albino's and some possible het's (66% I believe).
Make sense?
Ian