Spencer nodded, and after a little while, he said gently, "When I was little, there was a rather long period of time when mum had to stay in the hospital, and aunt Emma looked after me. She helped me through the loneliest time in my childhood. She's like another mother to me."
That was why Spencer felt close to aunt Emma even though his mother was not, even though aunt Emma didn't have a very good reputation.
I see. He probably means the time when mum got hurt and lost her memories. Nathalia thought while listening attentively. She looked him into his eyes with much affection and wished she could have been there for him. Then she thought for a little while and asked cheekily, "If it happens again, I mean, if she's rude to me again, will you stand on my side?" Aunt Emma is obviously someone important to Spencer. I don't want to have more conflicts between her and myself. Nathalia thought.