Take a look at the sentence again:
Sparkling with jewelry conned from ex-boyfriends, Sylvia keeps an eye out
for new victims with fat wallets, she still needs a pair of diamond
earrings to complement a necklace that she
managed to coerce Ricardo into buying.
No problem occurs between earrings and to. She still needs a pair of diamond earrings is a main clause. To complement a necklace is an infinitive phrase. An infinitive phrase will begin with an infinitive like to complement. When an infinitive phrase follows a main clause, you do not need to separate the two parts with any punctuation.
Go back to the sentence to try again.