Guarding is a serious behavior that must be corrected or it will get worse. Barney has been guarding his resources since he has been a puppy (probably due to early days at his puppy mill) and I have worked extensively with him but it will never be "cured" in this dog. Guarding from other dogs is not really that much of a problem but guarding from you is a very big problem.
I would strongly advise you to seek professional help on this so your situation does not get worse. One or two sessions with a good trainer would likely give you the protocol for the dogs.
Some tips in the meantime -
Make them work for everything. When Lucy is eating and you get near her bowl show her a piece of something high value - pieces of chicken - take it and put it near her nose, ask her to sit and then take the bowl. Put the chicken in the bowl and give it back. Do this a couple of times. She should soon associate you taking the bowl with you giving the bowl back with something better.
Regarding the bed - I would not allow them on it. Being on the bed is a doggie privilege and demands acceptable behavior for the privilege to continue. No toys or bones on the bed with this kind of behavior. If you remove toys and treats from the bed and there is still cranky behavior by Lucy, she is to be distracted with obedience with positive training methods. Do not punish her or she will keep associating bad things happening when Ringo shows up. (I'm on mom's bed, he shows up, I object, mom gets pissed at me, i get punished. Conclusion in dog's head: bad things happen (i get punished) when he (the intruder Ringo) is around.
Trust me I've done both of these methods and they work very quickly. As smart as dogs are, their brains are different and they only know good things and bad things. They do everything for THEMSELVES, not for you. If they do something for you, it's so they can get something (i.e. food) in return. Use their brains to your advantage.
Mostly, though, I will reiterate my initial comments that you need a professional trainer to help with guarding - a serious issue that needs serious and correct attention beyond a few tips here
Good luck