Michelle Obama as a woman of her own

The First Lady's speech on motherhood was inspiring, but of course she is so much more than just the "first lady".

At the opening of the Democratic convention in the United States at the start of this month, Michelle Obama spoke passionately about her role as a mother to her two daughters, her worries for their future, and her unwavering wifely support for her husband the president.

Her passion was grounded in a reality that most parents will recognise:

"Date night for Barack and me was either dinner or a movie, because as an exhausted mom, I couldn't stay awake for both," she said, with the insider's humour of the mummy club.

I love that line: it expresses exactly how I feel as a mother. I will bet that there isn't a mum in the world who heard those words who wasn't cheering at hearing them said out loud and in public, with honesty and pride.

Yes, it's really hard work being a mum. And yes, sleep, rest and ordinary pre-baby life experiences are what I miss most.

But I also hated that line, because its supposed praise of motherhood was in fact just a platform for her husband.

It wasn't her fatigue, the hard work and the value of motherhood that were being honoured in their own right - as they should be. It was all just building up to her role as a wife, to support her husband, showcasing him as a man who can tick off on his list a wife who knows her place and has everything in order. I'm all for mothers and wives being honoured and valued, but in their own right, not as trophies for their husbands.

Some parts of my feminist instinct bristled at her words: after all, Michelle Obama is an accomplished professional in her own right, something she wore as a badge of pride during the 2008 campaigning for the presidential nomination. Now she feels the need to play it down, and be the good homey wife.

Is America, the world's supposed bastion of feminism, looking at women and saying "this is the only kind of woman we should accept"?

But there's another part of my feminist instinct - and yes, I still feel it's a feminist instinct - that sees motherhood as a huge and undervalued investment in children. Our children are among our life achievements too. And of course it's worth saying that the same should apply to fatherhood and men.

Having my own 18-month-old baby, I don't have the same amount of time or creative energy to change the world as I had before she was born. But I'm starting to realise that two, five, or even 10 years of investment now can mean that my daughter will be better able to work to make the world better for another 30, 50 or even 70 years.

I want these competing motivations and feelings to be talked about publicly and to be acknowledged. That's why I was so disappointed at Michelle Obama's speech - those tensions were just smoothed out of the picture in favour of her man and in favour of her children. By the time she had prioritised all of them, there was nothing left of Michelle. Too often there is nothing left of the women who fade away behind the title of Mum.

Being a mum is a matter of pride. I believe it should enhance - not reduce - a woman in her own right. Just as a man retains his own identity while carrying the badges of father and husband, so women should be able to do the same.

Personally, I don't plan on fading anytime soon. Mum? Yes, and fiercely proud of it. Wife? Yes, and passionately proud of that. But I'm also still a woman - a person - in my own right.

Shelina Zahra Janmohamed is the author of Love in a Headscarf and blogs at www.spirit21.co.uk