They want you to bruteforce their bad stats through equipment. And even then her dex is hilariously bad for a trickster cleric.
Why does she need dex?
Dexterity determines Armor Class, AC means you are hit less by attacks.
Only armor type that ignores Dex on AC is heavy armor, but Trickery Domain cannot use Heavy armor.
Medium armor gets up to 2 AC from Dexterity. So a 14 in dex is "ideal" for a medium armor wearer.
Shadow heart has 9 in dexterity, meaning she has an AC "bonus" from Dex of -1.
Only characters that get's heavy armor should have Dex of less than 10.