had to put one dog asleep-

i had two German sharpards and 3 weeks ago we had to put one of then asleep, he was 13 years old, now my first problem is that my other dog cinda is buring her toys, i bought her all new ones and all she wants to do is take them outside and bury them. does this have something to do with her loss of her best friend Quasar? she is 8 years old. my next qusstion is ---is she to old for me to bring another dog--puppy- into the house in the spring? thanks djr