She held a tea gathering to introduce her daughter to her friends.

Literal

She [topic-は] daughter [object-を] friends [to-に] introduce intention [with-で] tea [possessive-の] gathering [object-を] held.

紹介するつもりでお茶の会を催した — つもりで ('with the intention of') marks the purpose. お茶の会 ('tea gathering') could be a casual tea party or a more formal tea ceremony gathering.