Okay. If Anakin's mum gave birth by her self here's how I see it.
Only aliens reproduce Asexually.
This is due to the cells replicating it self with Mitosis, and not the usual Human form Mieosis....
...My god, Shmi's an Alien, which makes Anakin an Alien, which makes Luke and Leia half Alien, which makes the Solo children 1/4 Alien!
If u read some of the new spoilers from MF, then u will see that many people think that Palps used the midichlorians to create Anakin.
The spoiler I was thinking of: Darth Plagueis