Hi Horizon. Welcome to the website! Even if a person is cremated, a funeral should take place. The cremains in the urn would be processed in to the church during the Mass instead of a body in a casket. I don’t know that this can be done without the knowledge of the family. Typically funeral planning involves the immediate family or the ones wanting the arrange the funeral. My understanding is that you would have to have some cooperation from the family.
As I always recommend, it would be best to contact a priest at a nearby parish to discuss the matter. He may be able to give you more specific guidance.