How do I handle this ?
Hi and welcome to the forum.
You obviously like your lovely friend. She is so excited about her new boyfriend all she wants to do is talk about him.
I think most of us can we relate to both you and your friend.
While it is frustrating and annoying for you to hear her talk non stop about the new bf, she is full of joy and is about to burst if she doesn't tell you everything about this new friend.
Can you get her alone and say how you think it is wonderful that she has a new bf , you would to have the time you spend together to talk about the two of you. Maybe say she can say one thing about him and then talk about other things. I am sure she has no idea that it is annoying to you as she just wants to share her happiness with her good friend.
I guess there is always a pang if you see a couple in love and you are alone. When it is you close friend and she is brimming with joy and goes on and on it can be especially wearing.
Actually as far as I can see both excellent and terrible fortune both make us talk. I'm sure you do not want to hurt you friend, and perhaps telling her direct as Quirky says might be the answer. If you think that she may be hurt and not understand there is another possible avenue of course.
You mentioned that the object of her desire is your brother -and that she even offered to send him around to cheer you up. Perhaps that is not such a bad idea. Are you close enough to talk to him and get him to have a word to her? Perhaps saying that constantly celebrating her good fortune reminds you of the fact you are not as lucky and that makes you down.
What do you think?