What great ideas you have received so far.

I don't know if she's into helping stray animals but if she is you can check with your local humane society to see what options they have for memorials.

I know a few herre that offer different things, you can pay for a memorial brick, they will engrave names/sayings on it and they add it to their brick walkway to the enterence of the building. Another shelter has a memorial wall where you purchase a brick, they engrave it as well and it is added to the building.

Or you can sponsor a dog in memory of her.

Did she get her dog cremated? If so how about a nice ern or even a small gravestone if they burried her.