Say or not to say

Hi. My ex's father has been diagnosed with a stage 4 cancer. I've been knowing this. Today, I want to tell her, my ex, that I love her. But I'm afraid it'd sound like I'm trying to be the center of attention or it'd sound fake that I tell it because her father is suffering from cancer. Or since she is vulnerable emotionally, it may sound As if I manupulate her feelings. But the truth is I just want her to know I love her. Should I tell her or bot to tell her?