Hard as it is to believe, not all attempts to set up business as a gite complex in France are a success. Unfortunately I don't know the figures for success and failure, but I have come across most of the reasons why the business might fail. I have deliberately written this in quite a 'negative' way, but that is only because it is better if you arrive well prepared for whatever challenges may lie ahead of you.
Property is in the wrong place
Sorry to say it, but the whole of France is not a tourist site, and some parts that are, are simply inaccessible. Despite low cost flights and improved roads, france is still a big country.
So if you are buying a property because it is beautiful and cheap, that is fine. But if it is somewhere no-one has heard of then it will be hard to attract holidaymakers to your property. It is possible to simply be in the wrong place.
There's nothing you can do later, except try and hold out for a buyer, so try to get this right before buying. Only buy in established or definite up-and-coming regions, unless you have a very good reason to believe that you can make a go of it somewhere else, or you are rich enough to take a gamble.
The most common problem. I talk about money elsewhere, but just a reminder - renovations are expensive, living costs are comparable to the UK, bills still need to be paid and children clothed.
You will not be able support a family on the income from one gite, unless it is a chateau. It can take years for gites to become established, and then prices might fall because Cyprus is cheaper this year, or whatever.
Living on an impossibly small budget while your funds run out is not a good idea, above all because it will make you much more stressed than you ever were before you came to France.
There are risks involved. As a minimum I think you should have 2 years complete expenditure requirements safe in the bank, in addition to the renovation fund, property buying fund etc. It will almost certainly take that long to get started and to get actual results.
This is the most common reason why people give up. To be brutally honest I have known families move out here where it was completely obvious they had no viable 'survival plan' for the first three months, never mind the first three years. And of course I can say that here because they are no longer in France...
Working 'on the black' as a labourer, fruit picker etc is not a viable long-term plan for you and your family. It takes one angry neighbour or resentful local to report you and it all comes to an end.
If you are not successfully getting visitors to your gites, but others in the same region are, it is likely that your marketing is being targetted badly. You might have the nicest rental properties in the world, but if no one knows about them they will remain empty.
Relying on friends and family spreading the word about how lovely the property is may work for you. It didn't work for us. Now after a few years we get quite a few return visitors, but this takes time to happen.
If you can't seem to get this right, read and re-read your adverts while trying to put yourself in the postion of someone searching for a holiday.
Try increasing the number of paid listing sites for the first year - you can always reduce them again later - and check that your prices are not over-ambitious.