
We had our oldest (almost 15 at the time, with a 12, 7, 5 and 2 x 2yo left behind) coming up on 2 years. We did it at home and let the 5 come and see her and sniff, so they knew she was gone. They all reacted quite well, except our next oldest (the 12 year old) had a rough time that night. She aged in just a few hours. We had a dog show scheduled for the next day and we decided to go to it, just to get ourselves out of the house. Savannah was quite bad that morning, brightened up a bit during the day when her Jr Handler arrived, and then when she saw her best boyfriend dog, and by the time she was in the ring at the end of the day she was almost back to normal. She was still very sad, but that deeply depressed look was gone. I sometimes wonder if we hadn't gone to that show, and stayed home being depressed ourselves, if she would have made it, or if she would have succumbed to the depression.
Similar to what someone else said, Chelsea (the dog we let go) had a spot in the bed behind my knees. She slept there every night of her almost 15 years, and it felt so empty. I wished one of the others would have taken it, but it took the better part of a year before any of them would. Now it's the most sought after spot, and they are forever edging each other out of it LOL.
It takes time. Savannah wasn't herself for several months. She was mostly happy, but she was just off. It was early this year that she finally came round and that was after we started her on an additional Senior dog supplement. I can't recommend it highly enough for senior dogs, and maybe it will help in your situation for your current oldie to help her get through
http://www.vetvits.co.uk/dog-supplements/multivitality-senior-formerly-trim-boost/productdetail-p15892-c1786997.aspx I'm always skeptical, but figure things are worth a try. This completely brought our girl back from the edge, and she's now coming up for her 14th birthday in a couple of months.
Best of luck finding the new normal. It will take all of you time to adjust.