Finnish to English Other General / Conversation / Greetings / Letters

I can't quite wrap my head around "sen sijaan tullut" in the following phrase (from a will):

"Määrään, että menehtyneen rintaperilliseni saama tai sen sijaan tullut omaisuus menköön [toiselle sukulaiselle]."
=
"I order that the property received by my deceased direct heir, or [??] property, should go to [other relative]."

I found an example that suggests "sen sijaan tullut" = "representing it", but if so, I'm not sure what "representation" would mean in this context.

Thanks