All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.
Tawaf al-ifaadhah is one of the pillars of Hajj. Hajj is invalid without performing it, and it cannot be compensated for by slaughtering. Whoever abandons this pillar remains in a state of ihram (ritual consecration), even if he returned to his country, until he performs it. In Al-Mughni, Ibn Qudaamah said:
Tawaf az-ziyaarah (al-ifaadhah) is one of the pillars of Hajj. Hajj is invalid without performing it, and one remains in a state of ihram until having performed it. If he returns to his country, then his ihram is not dissolved, and he is required to come back for it whenever he is able to. This is the only resort to make up for it. This is the opinion of ‘Ataa’, Ath-Thawri, Maalik, Ash-Shaafi‘i, Is-haaq, Abu Thawr, the Hanafi scholars, and Ibn Al-Munthir. Al-Hasan said that he needs to come for Hajj in the next year. A similar opinion was also reported from ‘Ataa’ as a second one, as he said that he needs to come in the next year to perform Hajj or ‘Umrah.
Accordingly, such young woman is still in a state of ihram, and it is impermissible for her to get married. The Prophet, sallallaahu ‘alayhi wa sallam, said: "A person in a state of ihram must neither get married, nor arrange the marriage of another one, nor should he make the proposal of marriage."
Allah Knows best.