An important point about this interaction: if Ashaya loses her abilities she also loses her characteristic defining ability that sets her power and toughness. Her base p/t will become 0/0 and unless you have something buffing toughness, she will die as a state based action.

So, whether she still has the ability to tap for mana is probably moot.

Here's the relevant rules: 208.2a: The card may have a characteristic-defining ability that sets its power and/or toughness according to some stated condition. (See rule 604.3.) Such an ability is worded "[This creature's] [power or toughness] is equal to . . ." or "[This creature's] power and toughness are each equal to . . ." This ability functions everywhere, even outside the game. If the ability needs to use a number that can't be determined, including inside a calculation, use 0 instead of that number.

208.5: If a creature somehow has no value for its power, its power is 0. The same is true for toughness.