Here's a bit of breeding info... I'm not trying to put you off, just to make sure you understand the realities of breeding bettas. To be honest, it's not something you can attempt with a single pair, and all the time in the world won't guarantee you success if you haven't got the money and the space. But please don't think I'm being deliberately discouraging, just honest.
It takes two to three weeks to condition a pair of bettas to breed, once both bettas are old enough. When you finally put the pair together, a lot of things can go wrong. The male can refuse to build a nest, either can refuse to spawn (if they just fail to get along, you will not get your fry), the male can wrap the female wrong (resulting in unfertilised eggs) and egg eating by either parent or both is quite common also. It's normal practise to have two pairs at a minimum and condition both at once so that you can swap partners if there are issues. Injuries - sometimes serious or even fatal - often occur during spawning.
A successful spawn usually produces between 100 and 300 fry. Within three or four days of spawning, you're going to need to have a suitable source of food. They are fairly easy to look after as newly hatched fry go, but enough baby brines/microworm/vinegar eels to feed that many fry for a few weeks, are probably going to cost a bit.
Deformities in betta fry are quite common due to the amount of inbreeding that has gone into all domesticated strains. You will need to be prepared to remove and humanely cull the deformed fry as soon as the deformities become obvious. I'm assuming that you have done some fish breeding before and are used to this. (If you haven't done any fish breeding, you might be better off starting with livebearers, as bettas are not easy fish to breed despite their reputation.)
By the time the fry are one or two months old, they'll be getting fairly big. You will need the equivalent of a 3 foot tank to grow out all the females in an average sized spawn. (Then you will need to filter and heat the tank/s). On top of this, the juvenile males all need to be separated or they will start killing each other. As soon as the fry become obviously dimorphic, you should start removing the males as they show themselves. This means cups. Lots of cups. 1/2 gallon jars or plastic canisters are ideal, but remember you have to buy these. You have to ask yourself if you've really got space for potentially 150 1/4 to 1/2 gallon containers, as well as a way to keep them warm. If they are 1/4 gallon or less, they will need daily 100% water changes. If they are 1/2 gallon you can stretch this to every second day, but that's still a lot of water changes.
By about 3 months, it will be possible to definitively sex most of the fry. At this point, you could start selling online because the quality of the finnage and colour is generally apparent by now. However, most pet stores will demand 5 to 6 month old fish and no younger, as people want their bettas bigger.
This is a good time to point out that the female you have is either a veiltail or a plakat. Breeders of fancy bettas are really not interested in veiltails any more. The breeding has moved well past this mutation, and no matter how personable and pretty some veiltails are, people want halfmoons and crowntails. They are rapidly losing interest in delta, and the only real interest in super delta is to supplement halfmoon lines. There is nothing wrong with breeding veiltails, provided the parents are healthy and strong fish, and you are able to find homes for up to 300 young bettas. You also have to ask yourself whether you are okay with selling to pet stores - the main market for veiltails - in the knowledge that the homes they will find for those fish are likely to be inadequate. (Cups.)
If you can answer everything on that list (if you've got the money, space, time, and heating capacity, and enough potential homes) then breeding bettas is extremely rewarding. Note that I'm taking the word of others here, because despite going through most of the first steps on that list, and associated expenses, several times, I have still not achieved a successful spawn. I should warn you that at times it is extremely frustrating, when after doing everything right, you are still faced with repeated failures. The feeling when you finally find eggs must be amazing. And I hope I haven't permanently put you off. I just hate seeing and dealing with the results of people attempting to spawn without being prepared.