Tvesa, who took the lead on the opening day, carded 76 which included a slump between third and sixth holes, during which she dropped three bogeys and a double bogey.
But she steadied herself on the back for an even par 36 with two birdies and two bogeys.
Millie, who struggled to a 78 on first day was level par 72 for the second and she moved to a total of 150, one behind Tvesa.
Amandeep Drall was a distant third with rounds of 76 and 79 and Gauri Monga (76-80) was lying fourth. Ridhima Dilawari, second overnight, and Ghazala Yassmin were tied for fifth at 158.
