Hi Jackson
When referring to the names of dead family members or other people with whom you had some kind of personal relationship, it is normal to use the past tense. Using the present tense suggests that such people are still alive and/or that the personal relationship is still current.
As a further example, if someone said "
The name of my boss at ABC Company is John Smith", I would interpret that to mean not only that John Smith is still alive, but also that the person currently works at ABC Company. If someone said "
The name of my boss at ABC Company was John Smith", my first interpretation would be that the person no longer works at that company. In other words, the person's business relationship with John Smith has ended.