Bella Woods felt entitled to negotiate with the Woods Family because Cyan Marshall had previously communicated with her and taught her step by step how to negotiate these terms.
Since it was a collaborative relationship, if the Woods Family couldn't come up with the money, the Hughes Family would have to cover it. Otherwise, halting the New City project would be troublesome for the Hughes Family as well.
Cyan Marshall had Daniel Hughes deliberately arrange for the Woods Family to be held accountable for this matter. However, knowing Bella Woods' connection with the Hughes Family, the Woods Family would certainly ask Bella to speak with Cyan Marshall, and Cyan's teaching Bella about negotiation was intended to protect her.
This was also why Bella Woods wanted to hide Ashton Marshall.
Cyan Marshall's affection and friendship were too profound for Bella Woods to repay, and she didn't want Cyan Marshall to know about her relationship with Ashton Marshall.