My elderly father, who needs a lot of support, lives with my brother and his girlfriend, who moved in about a year ago just a couple months after they started dating.

His girlfriend is a really good person and wonderful with my father, and I'm grateful that she is taking care of him so well.

However, I'm also very jealous of the relationship that they've developed, and it's obvious that this is the case. I'm polite with her, but my displeasure shows in my body language and facial expressions.

She's also a fairly assertive person, which I tend to dislike (I realize this is another 'me' problem), and this is what mostly irks me, I think -- somebody directing me about my father's care. Also, in the beginning, she seemed downright competitive and possessive about my father. It felt quite offputting and a bit weird.

She has backed off quite a bit when my sister and I visit, saying she'll give us some 'space' (which I also find annoying for some reason), but the whole situation is still getting on my nerves, and I'm ashamed that I'm jealous of this lovely woman and being so petty. And that what is a great situation, really, is getting on my nerves.

Help!