reality check
probably not the answer you were hoping for, but, just to be clear,
jacksons are;
1.imo not the best starter chams
2. in all but extremely rare circumstances need to be housed individually, you cannot house a m/f pair together, on rare occasions, experienced keepers may get away with housing a f/f pair but not recommended.
3. this means separate cage, lighting, heating, and all other husbandry equip for each animal as well as 2x fecal floats (fecal float is recommended for all new xanths, especially ones from a petstore. and 2x vet bills, the reality is, if you are not an experienced xanth keeper you will likely end up at the vet.
4. if a mf pair has been housed together then its reasonable to assume that the pet store selling them has not exercised very good husbandry, which means metabolic issues are likely already in progress that will have to be corrected. also means that the female is likely already inseminated, quite possibly from its sibling . imo neither stuation offers a good starting scenario for a keeper new to jacksons. if you are intent on getting one from the pet store which i also dont recommend, imo you would do best by getting just the male and leaving the female at the pet store
5. jacksons are metabolically sensitive and diversity in diet is more critical than with many non-montane species, ie, feeding a diet of mostly petstore crickets will almost certainly eventually lead to serious metabolic (health) issues
6. i realize probably not the answer you were hoping for, but better to find out the reality of the situation now than after you buy them. jmo