perhaps I'm just a control freak then . Not sure how a dog would be able to work out when it's ok to chase stuff with you in tow, and when not. But if it works for her, then so be it. doesn't add up to me is all. may also depend on what breed of dogs she has.
There are a few trainers around going down this route and to a degree I do this with Teal, very occasionally I let her chase a rabbit then stop her on the whistle but, and its a BIG BUT, Teal was steady for 3 years before I allowed this to happen.
The thinking on this I believe originated in the US, dogs are allowed to chase as a reward for not chasing, I have seen some video on this and it seems to work but the dogs were GSP's not spaniels, personally I would never try this when training a dog, especially one that has already learnt to free hunt and I have trained a good few gun dogs.
The only time I let a dog chase is when they are very young and before proper training starts I do this to encourage the pup to start hunting and kick in the prey drive. This is all very controlled and as soon as the hunt drive kicks in it is not repeated.