Hi Helen,
she may not need four meals a day now - some breeds and also simply individual dogs regardless of breed, are self regulating when it comes to meals - both quantity and frequency

The more often you add extras or goodies to her diet the more faddy she will become - done that more times than I care to admit. I'd pick a highly pallitable and easily digested food such as Nature's Harves / N Diet / N Menu - all moist completes and each readily available from PAH

As Brainless has mentioned they feeding guides on packets/bags are rarely accurate! I've yet to own a dog that NEEDS the recommended amount (but currently have one which would be more than willing to scavenge the lot LOL).
Skip the morning meal in part - that is, make it a "brunch" meal and adjust lunch to late afternoon and a third meal to as late in the evening as possible. If you're using foor for training treats its better to take the amount used off of her daily ration - that way she wont be getting too much nor should it fill her up. Personally I'd forget about treats/training until her meal is out of the way then offer a tiny bit of cheese for eg as a training treat but not in a quantity which would affect her appetite. Chicken is a preferred option (dogs and owners LOL) usually for training but as she's so faddy IMO it may be better to go the route of a non meat based treat

HTH, regards Teri