Yes. Just open up descr_campaign_db.xml in a plain text editor, like Notepad++
Find this section
Code:
<family_tree>
<max_age uint="99"/>
<max_age_for_marriage_for_male uint="65"/>
<max_age_for_marriage_for_female uint="50"/>
<max_age_before_death uint="100"/>
<max_age_of_child uint="4"/>
<old_age uint="60"/>
<age_of_manhood uint="5" />
<daughters_age_of_consent uint="12"/>
<daughters_retirement_age uint="50"/>
<age_difference_min int="-15"/>
<age_difference_max int="40"/>
<parent_to_child_min_age_diff uint="12"/>
<min_adoption_age uint="12"/>
<max_adoption_age uint="22"/>
<max_age_for_conception uint="55"/>
<age_of_manhood_close uint="16"/>
<max_number_of_children uint="4"/>
</family_tree>
Note: numbers may vary, mine are modded.
And change this line <max_age uint="x"/> to some high number (like 100), a character will almost certainly die before he reaches this age.
This line <old_age uint="60"/> to some lower number, but still high (95, for example). It's the earliest a character can die at from old age.
And this line <max_age_before_death uint="100"/>, to some number at least as big as max_age (105, for example). When a character reaches this age, he'll die instantly.