Simplify the following text for a Grade 5 native English-speaking person.
Original: According to Gilbert Burnet , however , Mary convinced her husband that she did not care for political power , and told him `` she would be no more but his wife , and that she would do all that lay in her power to make him King for life '' .
Simplified: But Mary told William that she did not care about political power . She said `` she would be no more but his wife , and that she would do all that lay in her power to make him King for life '' .