Do any of you have Jealous beagles?

So I love my Annie, she is my baby, my sweetie, and she knows it. I noticed her jealousy last summer, we took in a beagle rescue a sweet little girl who had been very badly abused before we got her, she was scared of everything, and required lots of cuddling to get her use to people and to realize we wouldn't hurt her. Her and Annie got along great, but Annie didn't like that she was getting her attention, she let us know it by peeing and pooping on the floor. After a few months we found Lacey a new home, we would of kept her but decided it would be best for her and Annie if they each had a home where they had undivided attention. Now we have my neices standard Poodle staying with us because they lost there house and can't keep him where they are staying now. She has started the peeing thing again. She only does it when we are not around. It took a few weeks for me to make the connection. She hadn't had an accident in a long long time, then all of a sudden almost every single morning I would wake up to pee or poop. She knew she had done wrong, and you could tell as soon as she saw u if you needed to be looking for where she had gone. We have started giving her a ton of attention, and sadly ignoring poor pee more. (She spends hours outside during the day so we love up on him then) and she has stopped.
I'm just curious if anyone else has had this problem? I see all of you with two beagles and I would love to one day have a second Beagle, but what about my jealous girl?