"Grandmother" is a word most people assume means a woman who has successfully raised another person at least to an age where they, themselves, reproduce (hence, the grandchild).
I am a grandmother, but as yet, haven't managed to actually accomplish raising a child. I have one... he is 7 years old. I also have a 29-year old stepson that I got when he was 17. He's where I got the grandchild from.
Don't get me wrong - I love my granddaughter very much - but I don't feel like her grandmother. I don't feel like I've passed the tests yet. In fact, I'm only two years ahead of her parents in the childrearing game... by no means an expert. I can offer limited advice when it comes to her, and she's very different from my own son in temperament and ability so I don't know how valuable even my limited advice might be.
She turned five this past week with a noisy, crowded party at Chuck E. Cheese's. I waded through a million kids to find her, and when she spotted me, she hurled herself at me screaming "Nana, Nana! You're HERE!". I scooped up her little body and held her close. It got quiet in the middle of Chuck E. Cheese where it was just me and her hugging each other. Just for a moment. Then the noise began again and she wriggled to get down and play some more. A final squeeze and I let her go.
Maybe I am a grandma after all.