I must agree with the substitution of Thomas. Without further evidence, it would not be clear which place in CP was wrong, but ODNB agrees (and does not call any of the last four Lord or Lady Cobham). Your extract from Cockayne omits that the second Lord Cobham and his wife were cousins; after the birth of their son, they got an annulment and remarried; the son had to sue for his inheritance.    PMAnderson