Don't worry, you can get her on the next playthrough.
“I agree. Now tell me about the attack on the shrine before I do anything else.”
Her eyes become stressed, and she makes a small gasping noise.
“You agree already? Really?”
“Yes, I do.”
She smiles and leans over to pat your head.
“Good girl. Well, I guess I still owe you some more info, so here I go.”
She takes a deep breath, and begins to explain again.
“The attack will be fairly simple. I’ll wait above the shrine so my presence can allow Ran and Chen to distract Reimu and Mima from noticing you, and then you will have to eliminate that ‘Nanaya’ man. I hear he’s pretty powerful, but…”
Yukari blushes again, and seems to be a little nervous about telling you something.
“Well, I took a peek into your mind. It seems like you are on at least the same level as him, and you could probably ascend to godly levels of power in a pinch.”
The idea of her doing this enrages and confuses you, but you contain yourself.
“So, do you understand the game plan, then?”
You nod, and Yukari pats your shoulder.
“Good, good. Anything else you’d like to ask me, then?”
A thought pops into your head.
“Can I call you Mom, Yukari?”
She looks shocked. She fidgets with her hands, swallows, and then talks again.
“Well, the last person that called me their mother was Ran, but… I guess I could be your mom.”
She turns her head to hide her embarrassment, and asks you another question.
“Now then, where would you like to go for now?”
[ ] Ask her to take you to Chen and Mystia.
[ ] Ask her to take you to see Ran.
[ ] Ask her to take you to see someone new.
[ ] “I’d rather stay here right now, Mom.”