The doubles is very strong here. The cut off for the Advance List was a CR of 63 and the 2 on site doubles ranking entries having CRs of 65 and 66. Heather would have needed to have teamed up with someone in the top 20 to make the draw. Voskoboeva is the only player lower ranked than Heather that is in the draw who entered with their doubles ranking and she only made the draw because she teamed up with Mladenovic.
If Harriet wins her R1 match her next opponent will be Daria Gavrilova (AUS) 35 or 8th seed Anastasija Sevastova(LAT) 11. Harriet played Sevastova earlier this year losing 3 & 4.