。
She entertains every guest she invites with warm hospitality.
Literal
She [topic-は] whom [object-を] invite [even-ても] thickly entertains.
誰を~ても ('no matter whom one X-es') pairs an interrogative with the concessive ~ても for a universal-quantifier reading. もてなす ('entertain, be hospitable to a guest') is the verb behind the cultural concept おもてなし ('hospitality'), a near-untranslatable Japanese ideal of anticipating and meeting a guest's needs without being asked. 厚く is the adverbial form of 厚い ('thick'), used metaphorically for 'generously, warmly, lavishly' — the same metaphor English uses with 'thick / lavish hospitality.'