Bullock and husband Jesse James, who tied the knot in 2005, are applying for full custody of his youngest child, five-year-old Sunny. Sunny is James' daughter with his second ex-wife (Bullock is the third Mrs James), porn star Janine Lindemulder.

Lindemulder made her pornographic debut in 1992 after a decade of modelling in Penthouse, and until retiring almost a decade ago she was one of the industries most prolific actresses in girl-on-girl films. When she came out of retirement in 2004, three months after Sunny's birth, she began working with men on screen for the first time.

If, like me, you don't recognise Janine from one of her porno flicks (she's featured in such gems as Janine's Got Male, Janine's Been Blackmaled, WMB: Weapons of Masturbation and the Where The Boys Aren't series, Parts 1-13) she may seem familiar from the cover of Blink-182's 1999 album Enema of the State. She also appeared in the video for the band's song ‘What's My Age Again?'

Watch Janine in the video here.

So she's a prolific porn star. It's not an occupation everyone would be proud to put on their immigration form, but it's not a crime. But what exactly has Ms Lindemulder done to be threatened with losing custody of her child?

After a long struggle with drug addiction, Lindemulder was jailed in December last year after pleading guilty four months previously to tax evasion. She had avoided paying the US government over US$200,000 in back taxes, and was given a six-month sentence in federal prison.

While her mother was in the slammer (she now plans to write a book about the lesbian encounters she had with other inmates) Bullock and James had a temporary order giving them full custody of Sunny. They're now looking to make that order permanent.

James and Bullock have no children together, but James has two older children, Chandler and Jesse Jr., from his first marriage. Lindemulder has a teenage son, Tyler.

After the couple officially applied for custody of the little girl, Lindemulder came out on a US TV show with all guns blazing.

Insisting she's a changed woman, Lindemulder says Bullock has ‘no right' to take away her child. Bullock has denied Lindemulder's claims that the reason she desires full custody of Sunny is that she can't have children of her own.

"I do believe the reason Sandra is so interested in Sunny is she is saving Sunny from me - from her own mother. That is what I believe," she said in an interview which aired this week.

Lindemulder told Good Morning America that because a court order bars her from working in the porn industry, she intends to forge a career as a tattoo artist. She also says she is clean from the drug problems which plagued her past.

"I am the best mother I can be. Yes, I have absolutely made horrific choices in the past. I've had my share of drugs.

"But then there's a huge portion of my life, a 10-year span, where there's nothing - I didn't need it."

For their part, Bullock and James obviously don't believe Lindemulder's claims that she's clean and sober.

In a letter submitted to the courts, Bullock states: ‘While in Janine's care, sometimes Sunny is left alone during the day, while her mother is asleep from drug use.'

James, who submitted his own paperwork, claims his ex kept secret her remarriage to her third husband, whom he refers to in the documents as ‘a two-time State and Federal felon.'

So on one side you've got the good-girl movie star and her motorcycle building, TV star entrepreneur of a husband. Free of addiction, smears on their reputations, criminal convictions, and with plenty of resource to raise a child in a happy and loving home.

On the other side you've got the former porn star, drug user and convict, married to a felon and with not much in the area of job prospects since she can't go back to the sex industry she knows so well.

Sandra and Jesse are no doubt a far superior option - but Janine is still that little girl's mother. If (and only if) she really has cleaned up her act, surely for the kid's sake she should be given a chance? Liberal visitation rights or a shared custody arrangement must be able to be sorted if she can show a track record of clean living and a serious commitment to getting her life back on track.

If not, naturally full custody should go to Sunny's father.

Then again, would anyone be championing the cause of a parent with Janine's history if it was the child's father? Maybe not.

I must say I think Sandra Bullock is fab. Not a massive fan of all of her movies, but love that she looks natural and isn't starved to billy-o or Botoxed up to the eyeballs. Love that she was never desperate for the marriage and babies thing, happy to be on her own until the right man came along in her early forties.

Love that she adopts diabled dogs nobody else wants. Love that she has a place in Austin, Texas to get away from all the hoo-ha in LA. And loved the idea of her low-key wedding - arriving in a pick up truck, hay bales and cowboy boots. She may have plenty of mainstream romantic comedies under her belt, but with plenty of clout as a producer this woman marches to the beat of her own drum.

All Lindemulder wants, she told Good Morning America, is a chance.

"Sandy doesn't know what goes on in my house - I'd love her to. Please, come over! I'll make dinner. You know, let's sit down, two women.

‘It hurts tremendously. The accusations, especially from Sandra, because we've never sat down and talked.'

SUBSCRIBE TO MY TWITTER FEED HERE