Do you and your aunties share how much blood?

Answer 1

The first thing to understand is that "blood" is metaphorical. You don't "share" any actual blood.

Statistically, siblings are related genetically by 50% ... each child gets 50% of each parent's DNA (it's random which 50%), so on average you'd expect that about 50% of your mother's DNA is identical to that of her sister.

You get half your DNA from your mother, so (again statistically) you'd expect that 25% of your DNA is identical to that of your aunt.

It's complicated slightly because it's possible (but statistically extremely unlikely) that your mother and aunt have entirely different DNA, but on average you can expect to be about "25% related" to your aunt because you're 50% related to your mother (always true) and she's 50% related to her sister (on average).