Is it really uncommon to not think of this?

I got contacted recently by an ex friend who I broke ties with 3 years ago.
There's been one thing that's been steadily bugging me about this.
She said she's been trying to contact me for a long time but not long after I quit talking to her she lost my number and since I blocked her on Facebook she didn't know how. She contacted me recently by having a friend who wasn't blocked contact me in her place, she said she just thought of that recently.

I assumed she was lying because I can't imagine it taking anyone 3 years to think to have a friend contact me in her place but when I told a friend about it they said most people aren't as meticulous as me and he could see someone not thinking about it, and my dad said ,''she was never she sharpest tool in she shed'', so I don't know.

Is it reasonable to believe it took someone 3 years to think to have a friend contact me on facebook in her place?