By the way, isn't she technically her mother?

If you like "Previous Generation" as "Mother"

Although I feel its more like adopted girl route

Gigawatt5 said:
By the way, isn't she technically her mother?

Nah, it doesn't matter who inherits the Hakurei duties as long as she qualifies for the job according to Aya.
They could have any kind of relationship or none at all.

...Upon closer inspection I noticed something I think... Is Reimu... crying?

the mother thingy would explain why she's not in business anymore (being a shrine virgin is and mother is pretty hard stuff...)

Kuji-kiri said:
it doesn't matter who inherits the Hakurei duties as long as she qualifies for the job according to Aya.

If by "according to Aya" you mean "according to this unsubstantiated interpretation of one sentence Aya said that doesn't directly state nor imply any such thing", then perhaps.

In any case, in as far as the Sendai Hakurei Miko was given a backstory in MUGEN, she's definitely not Reimu's mother. However, fans like to interpret it otherwise.

HakaimaRan said:
...Upon closer inspection I noticed something I think... Is Reimu... crying?

She's in melee range, facing the miko who held the whole of Gensoukyou together with no silly spellcard rules, but with pure skill, brute force and overwhelming power. And that fist is now coming right at her face.

Yeah. I think she'd be crying.