Guarding issues

I noticed yesterday while out with tattoogirl that Kiara was a bit grumbly initially with Opie, I just put it down to Opie being rather bouncy and loud

Kiara settled down when we were out and was ok with him until we got back to Jayne's, I was sat outside keeping an eye on the dogs while Jayne made a cuppa and Opie came up for a cuddle, Kiara immediatley came over and shoved her nose under my arm and started grumbling at him Opie moved away and Kiara wandered off and was fine again until Opie came near me then she did the same, she just didn't like him being near me

Kiara didn't full on growl, no teeth showing or anything like that but it was a definate grumbly growl type thing that she did.

Do you think she thinks she's protecting me?? If this is the case I'm wondering if this is something else that Bailey reacts to that makes him dislike dogs, as I'm sure he'd hear the grumble even when she's not right by side. He's much better with other dogs when he's on his own rather than out with Kiara and Poppy.

Also if it is - How do I stop it??

She is not protecting you as in guarding you from harm.

She is resource guarding you so protecting her asset from approach by interlopers.

You need to explain to your dog that other dogs are allowed to approach you for food, play etc (if that is what you want), you can start this by teaching dogs to take turns ie in play or in taking treats.