Gretel is very cute, has she got a bit of show type in her as well? I work my dogs and they live in the house - would Rodaidh be a more focussed working dog if he was kennelled, quite possibly, but I have no problems with him as he is, he's an excellent worker and very biddable so it's never been something that I've contemplated doing with him. However, it is something that I may well do in the future at least part time if I have more field trial dogs; my youngest bitch, Caoimhe, is a trialling dog and she is kennelled for most of the year when she's with her handler and it does improve her focus, she switches up a gear into performance mode when she's in the kennel environment. However she lives in the house when she's with me and once she's retired from trialling and 'just' a working dog she'll be inside all the time like the others.
If your dog is ignoring you and bogging off you need to make things more interesting for her to keep her focus on you and don't give her the chance to get away, don't let her go any more than a short distance from you. If she likes retrieving game then take a bird or rabbit with you and use it for training, I almost always take a pigeon or rabbit (I keep a frozen supply) when I'm training Rodaidh and Caoimhe - Caoimhe will retrieve anything although dummies don't exactly set her world on fire after the amount of game exposure she's had and Ro will barely waste his time picking up a dummy now that he's had 3 seasons out working on the real thing. The game should keep her attention on you a bit more, you can hide it for her, plant things for her to find etc. If she's repeatedly bogging off and/or chasing you need to go back to basics, go after her and bring her back to where she was when you first whistled her and she ignored you. I used a trailing line on Caoimhe when she was a pup so that she never got a chance to get into the habit of ignoring me or going too far away (no more than about 6-8 feet to begin with) and especially never, ever chasing anything. You really need to stop that behaviour now as the more she gets the chance to do it the less likely she is to ever make a trustworthy working dog. I wouldn't let her hunt any gamey areas until you've got her steady and trustworthy or you'll keep putting yourself back to square one - 'boring' areas only for now and then gradually up the distraction levels. There are a lot of scents etc. around just now but if the steadiness is there it shouldn't have too much of an impact on the dog.