Please register to participate in our discussions with 2 million other members - it's free and quick! Some forums can only be seen by registered members. After you create your account, you'll be able to customize options and access all our 15,000 new posts/day with fewer ads.
I'm very sorry for your loss. It doesn't sound like your situation contributed at all to her being ill. A friend of mine found a pet bereavement group very helpful. If there is one in your area, it wouldn't hurt to check it out.
If you get another female dog in the future, spaying her will eliminate the pyometria risk and vastly reduce the risk of mammary tumors.