。
She has the right to inherit her late husband's estate.
Literal
She [topic-は] dead husband of property of inheritance-right [object-を] possesses.
相続権 ('inheritance right') is a legal term — 相続 ('inheritance') + 権 ('right, authority'). Japanese inheritance law gives the surviving spouse a default share alongside any children; the specifics are governed by the 民法 (Civil Code). The chain of の's stacks possessors and attributes: 死んだ夫 → の財産 → の相続権 ('the inheritance right of the property of the deceased husband'). 財産 here covers any holdings — real estate, savings, possessions. Each の links one element to the next.