Surrendering my dog

I have had my mini aussie for about 5 years. She started getting aggressive after my husband passed away. She got a little better but now she's back to being very aggressive with my chihuahua. I've been bit because I put my hand in the way of her fighting. Im scared to leave them alone. Im afraid she'll kill my chihuahua. I dont want to do this but can I surrender her to you and hopefully you can help her and find her a farm to live on. She's a work dog.