Last night, a vendor came to my house and asked me to buy some fruits (from her). Because it was late and she wanted to go home with everything sold,
she was selling at very cheap price. I was able to buy dozens of mangoes and guavas (4.5kg) for
only 45000 VNĐ (about 2$). She said "thank you" many times but I think I should be the one to say "thank you" to her.
She can't "go across" your house. She can "go through" it (entering the front door and leaving by the back door), or she can "go across your property" (which means, for example, walking across your lawn.)
Did she knock at your door? If so, I would say she "came to" your house. If she did not knock on your door but merely saw you outdoors, I would say "a vendor passing by my house asked me...".