This is the only information I was able to find:
Cristobalina is a low chill Spanish heirloom variety. It is self-fertile and requires about 200 chill hours. Cristobalina has been grown for generations of cherry growers in Andalucia and Valencia, where winters are as mild as they are in Southern California, and reliably produces fruit despite lack of a cold winter. It is known to flower mid-February and produces dark purple, delicious sweet cherries. The only negative is that the fruit does not have as much edible flesh as other more popular cherry varieties, but thinning the tree can help lead to more full-sized fruit.
There has been some speculation that Cristobalina may likely have been used by Zaiger to breed Royal Lee and Royal Minnie.