Am I being manipulative?

I have known a girl for 12 years since high school. We had crushes on each other back then but didn't date. She told me she loved me while she once dated one of my old friends (I actually introduced him to her) for years. Now, she is single and when asked again recently if she did love me before, the answer is positive.

I am not attracted to her, so I treat her as my best friend with whom I message everyday, sharing my laughters and tears...Interestingly, she never seems to feel exhausted despite hearing so much from me.

We live in different countries and haven't seen each other for years, so I choose to keep everything platonic, but am not sure if this sounds manipulative.

Personally, I have never dated and don't know what love really is.

Knowing that she has feelings for you I find it slightly dishonest and disrespectful to continue to speak to her on a regular basis as you do. Even if it’s long distance, you are maintaining her hopes and preventing her from moving on. Imo it’s time for you to find another friend to chat to and for her to find someone else to feel close to.
It’s time for you to tell her the truth about how you feel.

I have known a girl for 12 years since high school. We had crushes on each other back then but didn't date. She told me she loved me while she once dated one of my old friends (I actually introduced him to her) for years. Now, she is single and when asked again recently if she did love me before, the answer is positive.

I am not attracted to her, so I treat her as my best friend with whom I message everyday, sharing my laughters and tears...Interestingly, she never seems to feel exhausted despite hearing so much from me.

We live in different countries and haven't seen each other for years, so I choose to keep everything platonic, but am not sure if this sounds manipulative.

Personally, I have never dated and don't know what love really is.

Yes...maybe. I have had several crushes since my crush on her ended, i.e. I no longer have romantic feelings for her, so I guess I'd raise this issue when appropriate.