How long had you had the pair, before her passing, how large is the enclosure?
From what is notable in the limited photos, you have a fairy typical, though sparsely furnished cage, which, being all screen is likely rather dry to a montane jacksons. Cohabitation is a hot button subject and some of use break the rules and things can work, but in any cases where this is successful, cages are large, DENSLEY furnished, and the species, as well as individuals are carefully monitored and selected, with perpetration to intervene, if there's trouble.
Your male looks, at a minimum, dehydrated.
If I were you, I'd do several things, differently.
First, I'd separate the two animals, this includes visually, so they can't see each other. Second, I'd cover 3 sides of that screen enclosure with material to hold in humidity and I'd employ a humidifier, fill the enclosure with LIVE plants, and review the care parameters for the species. Next, I'd get both animals checked out and at least 3 fecal sample, spaced a week or 2 apart, from both animals, checked for parasites, then every 6 months, I'd have another tested. Once that is done, you'll be on your way, hopefully.