I'm so sorry.

My brother went through this with his big dog (maybe Mastiff mix) when he had his Husky put down.

Cleo avoided him for a long time;
the vet told him, after the fact when it was too late, that the last time Cleo saw Tasha, my brother was driving off with her.

Vet said that dogs accept death, all they have to do is sniff their old friend's body, but that they don't understand disappearance.

I can't remember what if anything he did to overcome this, or if he just had to wait for Cleo to forget.

Again, I'm so sorry.

That may be, but it also may be a grief reaction. When I lost my big yellow long-haired tom, his partner and companion, my little black female tortie steered clear of humans too. He was killed in an accident. She had time to sniff his body, and her reaction when she understood he was 'gone' was so human-like it brought us to tears. It was a look of horror. She kept to herself for several weeks, sitting where they used to sit. Then, she appeared very skittish when she decided she wanted human company for a few more days, and then it seemed like she was over whatever she was working through. I just was super gentle with her, and let her have her space and after that, she became more clingy and wanted more companionship from us. I'm sorry for the loss of your Lucy.

She'll be fine, she needs some time. You said "yesterday" so it's only natural she'd be wondering what's going on.

I agree with the others, she needs time just like we do when we grieve, my heart goes out to you & your family.
Christine

I was just thinking about something..maybe you are crying or have a strange sound of sadness to your voice and your dog is detecting it and doesn't know what to make of the way you are acting? I bet that's what it is! I bet your surviving dog thinks you are upset at her. Try as best as you can under the circumstances to act normally and be more upbeat.

Thank you for the replies, I appreciate it. Stella and I are both doing better today, she is back to laying next to me on the couch and I am trying to go about my business as usual. I guess she just needs some time to figure it all out. She has always gotten mopey when my son leaves with his dog, but has never rejected me before, so I wasn't expecting that. She still looks for Lucy when I go to take her out, she is used to herding her to the door, but is getting better about it. We are traveling at the end of the week, hopefully the change of scenery will help all of us.

Do you have a piece of bedding or a toy that Lucy was fond of? Stella might find her odor comforting right now.

I agree. Something with Lucy's smell on it may help her adjust. My sympathy to you and Stella.