Was it her mother who had initiated contact with Duke Residence back then? Or was it Duke Residence that had sought out her mother?
Considering that the Nanchu Queen wanted to kill her, there was a high probability that her mother was Princess Zhenmin. If her mother had sought out Duke Residence, remembering her mother's contribution to the salvation of Daliang, even if it was difficult, knowing she was trouble, they might not be able to refuse, right? If Duke Residence had sought out her mother, this was practically impossible. Since her mother had concealed her name and identity, even the Empress Dowager and Emperor did not know of her whereabouts. It would be impossible for Duke Residence to know unless she had something to ask of Duke Residence.
Thus, her engagement with Zhou Gu should have been sought by her mother.