Here is a small part of the Jacksonii article from Petr Necas' book Nature's Hidden Jewel, 2nd edition. Basically, it says that Jacksonii are gravid for a period of 6 to 7 months, for an average of 174 to 236 days. Usually in the morning (10 to 12am), she gives birth from 7 to 51 babies. Giving birth may last between 30 minutes to 4 hours, and the female is ready to mate again in about 20 days.
The high difference between the Necas' numbers and yours are worrying me, and if you believe she may still be pregnant, you better find yourself a good and specialized vet to make sure everything is Ok. You may disagree with me, but a good visit to a vet is worth it, even if it's just to make sure everything is alright. This way, you'll see safer, and you will be sure your jacksonii won't die in your hands. At least, this is what i would do.
Once again, this is just the opinion of someone who just read 2 pages of a book without knowing anything else on your species. I can be wrong, i can be right, but in doubt, paying a good vet a visit is always worthy!
Good luck to you, and keep us updated please!
