Once fleas get into the home environment it is difficult to get rid of them, but it can be done.
First realize that only 5% of the flea population lives on animals, the rest is in the environment. Whether you choose to let her come in again or not is entirely up to you, but the flea problem will continue whether she comes in or not as they have established themselves in your home. Although fleas prefer to feed on pets if they are not available then people will get bitten as well to get a blood meal.
Your initial plan to vacuum and treat with Indorex was a very good one.
Here is the protocol I give to owners with flea problems:
You need to vacuum your home throughly to remove as many eggs and larvae as possible. Concentrate on cracks and crevices, along baseboards, under furniture and areas where pets like to sleep and eggs and larvae are at their highest numbers. Vacuum daily and throw away the bag. If you have a bagless vacuum then you will need to spray the cup with an area treatment spray. The heat and vibrations of a vacuum will stimulate any eggs that are picked up to hatch out. If we don't kill them in the vacuum the act of using the vacuum can actually hasten their development and you'll end up with more fleas developing at a quicker pace.
When you wash bedding (yours and hers) it must be washed in steaming hot temperatures. Eggs and larvae will survive normal wash temperatures.
You also need to use effective products on her. I recommend either Frontline Plus or Advantage ll as they are effective and safe products and both contain ingredients to kill adult fleas and make the eggs that they lay unable to develop. If you have been using regular Frontline that only contains an adulticide which won't be quite as effective, and will take longer to work because it only addresses the adult part of the population. Do not bother with over the counter products, they are neither effective nor safe in many instances. Flea preventatives should be applied every 3 weeks if you have an otherwise healthy cat in a problem situation as the effectiveness does wane a little after 3 weeks. If you have other pets all animals must be treated or they will serve as flea reservoirs.
I also recommend treating the home environment with a product that has an adulticide (kills adult fleas) as well as an insect growth regulator to stop egg and larvae from developing. A great product is Siphotrol II Plus Premise spray. I like it because it has an insect growth regulator as well as an adulticide. You can spray it under furniture and into cracks crevices and along baseboards where fleas and their offspring hide in areas where there are hardwood floors or tile/linoleum. All carpeted areas must be sprayed completely over the entire area. The eggs and larvae can easily attach to the base of carpet fibers. Environment sprays should be used every 2 weeks and no vacuuming for 2 to 3 days after using it to allow it to settle in. Here is a link to show you the Siphotrol product: https://www.amazon.co.uk/Siphotrol-Plus-II-Premise-Spray/dp/B000KVSTC0
Looking at Indorex it seems to be a fairly similar product, but I don't have any personal experience with it.
The trouble with foggers is that they don't go under furniture or penetrate cracks and crevices so they just aren't effective where they need to be. And they end up in the air where they are nasal irritants for animals and people alike. I do not recommend them.
Your other option is to have a professional exterminator treat your home and outdoor perimeters since goes outside. Ask for a guarantee and make sure that the products they use don't contain organophosphates and do have an adulticide and an insect growth regulator.
The key with flea treatment is consistency, not stopping too quickly, and using effective products.
If you choose to let her back into your home you should plan on applying flea topical prevention on her every 3 weeks all year round even once you are able to rid your home of fleas. That is the best prevention.
Please let me know if you have any further questions.