The Queen of Pentacles represents a practical, down to earth person, who's focused on everyday matters, financial stability and material security. The Queen of Pentacles often represents a person of an earth sign/ascendant (Virgo, Capricorn, Taurus). The Eight of Wands is called "swiftness", because it foretells fast and at times unexpected news and developments. It shows that very soon things will come to a conclusion and a goal will be achieved.
To understand the elemental relationships between the cards, we should always take into account their actual meaning. The elements of the cards are Earth (Queen of Pentacles) and Fire (Eight of Wands). The Fire card can energize and expand the energies of the Earth card, while the Earth card offers a stable base so that those energies are materialized in an practical and consistent manner. In this case, the two cards support each other, and the Eight of Wands would add the necessary force for the goals of the Queen of Pentacles to manifest and in fastest and most efficient manner.