You can eliminate any food issues by taking the easy way out and feeding them separately. That's what I did - otherwise, Ringo would have had ALL the food when Lucy first came home.
Sounds like she may be jealous of the new arrival. Perhaps give her some special attention so she doesn't feel insecure about losing her status in the house. Try note to pay more attention to the puppy than you do to her right now. I know that's hard when you have a new little one.
If she continues her guarding behavior - especially with you - I'd put her in another room for a little while. We did that with Ringo when he started getting possessive of me, usually of an evening. If he growled at her while on my lap, then he had to get off my lap. It really didn't take him long to figure out that good things happened (playtime, treats, walks) when we all got along.
Good Luck.
__________________  Mommy to Lucy, Ringo, and Matthew |