Wendy believed that Lance used to value Marc greatly.
She might have long since severed her ties with Moses and married someone else, but Marc was still her own flesh and blood after all. She would send people to keep an eye on the Kingstons from time to time and report the situation about Marc to her.
According to the information she had received, Wendy could indeed believe that the Kingstons had treated Marc well in the past twenty years, especially when he slowly grew up and revealed his intelligence and resourcefulness. Among all the Kingston descendants, her son was indeed treated the best.
Lance indeed didn't lie about it.
Lance had been secretly paying attention to Wendy's face, and when he saw that she seemed rather calm and didn't have any other large emotional fluctuations, he continued, "The person who caused all this is that punk named Lucas Gray!