We've been in the gîte business and I confirm that most owners I met were doing it all themselves and not looking for outside help. The labour laws in France make it risky to employ someone, particularly for a small business, because it is a/ expensive b/ admin nightmare to get rid of someone. Largish gîte owners that I know who have help rely on family, near friends, or neighbours to help out at peak times.
A few comments.....as above you may find it difficult to get salaried work in this area. If you go the tree surgeon route as an independent you will probably need to have the appropriate training certificates.....almost certainly the mandatory insurance will need these.
Gîte cleaning between lettings is a miserable and hard business. Sometimes it is easy, sometimes terrible if the outgoing clients have made a mess. We employed an experienced cleaner who had hotel cleaning experience....and she needed it on a Saturday when she had several gîtes to clean between the magic hours of 10:00 (exit) and 16:00 (new arrivals). She had professional skills way above the average housewife.
You might wish to try getting into the "stand in " business.....gîtes owners find it hard to take holidays. Try contacting owners on English speaking web sites?
An important part of running a gîte is the meeting / greeting and subsequent leaving bit. This would require passable French. There's a bit of admin involved - not difficult, but you need to know the French ropes.
If you have found your area (Aquitaine, beautiful!) try looking at the "office de tourisme" info. You may want to look for owners who have a large number of gîtes (5+). They are more likely to need help!
The French economy is beginning to turn round and the unemployment rate is less horrible than it was. Employment opportunities may be getting better?
Good luck
DejW