@BZF- I believe the zoo has four Ring-Tailed Mongoose- the pair on exhibit and their offspring. At least that ZooLex thing you posted (I think you posted) says they have "1,1+young".
ZooLex descriptions tend to indicate the number of individuals the exhibit is designed for, rather than the actual number held, so I'd be wary of reading too much into this.
Usually when a website such as Zoolex says that it means that the zoo is capable of holding a adult pair and there offspring but does not mean there are offspring currently.