"We got off to a great start in the first half," said Purdy coach Eli Ernst. "We were able to use our defense to create offensive opportunities."
Mattie White exploded for 18 first half points to help ensure the solid first half.
The Lady Eagles (6-2) led 17-5 at the end of the first period and 27-11 at halftime.
The Lady Cardinals pulled within 13 points at 27-14 but the Lady Eagles were too much outscoring Miller 12-8 in the third period and 20-14 in the final quarter.
"I don't think we have found our complete offensive rhythm," said Ernst. "We still have too many turnovers, and we have a tendency to rush possessions.
Scoring for Purdy: Mattie White, 21 points; Courtney White, 8; Katie Hughes, 7; Billie House and Jayse Henderson, 6 each; Desirie Ennes, 1.
Purdy hosts Wheaton tonight. Tipoff is set for 5 p.m.