Is a small amount of wetness that a woman notices considered moisture that invalidates wudu, or is that which invalidates wudu only the sticky, mucous-like discharge? And is it permissible to clean the vagina internally with a tissue to maintain wudu, especially when it is difficult to perform wudu outside the home?

Vaginal discharge is pure (tahir), but it nullifies ablution (wudu') if it exits from the inner parts (batin). However, if it is from the outer parts (zahir), like sweat, it does not nullify ablution. If there is doubt about whether it exited from the inner parts, the default is that the ablution remains valid. If the discharge is continuous, the woman should perform ablution for each prayer after its time has begun and pray as much as she wishes until the prayer time expires. She is not obligated to pray immediately after performing ablution. For those who find this difficult, they may adopt the view of the Malikis, which states that continuous discharge does not nullify ablution. There is no obligation to wash the inner parts of the vagina or its discharges, as they are pure.