I'm not sure about the fat content etc. of lobsters, but you really should have considered her weight long before now.
The quality of her life is very poor, I speak from seeing geckos less over weight than her have all sorts of movement problems, and worse yet, the same kind of issues that humans have when overweight.
Can you consider a different food source? Judging size wise, this is way more food than I feed my 10" female leo, and she's a healthy weight. She's on the 3 "large" cricks every 3 days. I wish I had Mader handy, but I suspect that roaches may have different nutritional composition - mealworms and crickets are pretty close to eat other. I understand you say this feeding schedule works for your other geckos, but consider the idea that if you are releasing too many into her enclosure, instead of ignoring them, she might feel she *has* to eat them to keep them from bugging her. She may be eating in self defense, if that makes any sense at all to you.
I would cut back to feeding only twice a week if you are insistent on the roaches. I would consider other food sources as well. Monitor her weight and try to drop her slowly, but please drop her. She has possibilities of long term health risks due to the stress on all her systems.
I often wonder if overweight geckos have a harder life than underweights...