Now, she has turned her attention to the early years, offering up data-driven answers to everything from weaning to potty training to vaccines. With the proliferation of conflicting and anxiety-inducing parenting advice now available online, it couldn't be more relevant. Let's hope someone gets a copy to Britain's newest thinking parents, the Duke and Duchess of Sussex (the Duchess has previously said she avoids Twitter, and instead reads The Economist).
Oster tackles contentious issues such as sleep training, otherwise known as letting your child 'cry it out' so they learn to fall asleep on their own - a dilemma that, in my experience, divides families like no other. "It works," she tells me down the phone from her home in Providence, Rhode Island, where she lives with her economist husband Jesse and their two children, Penelope, eight, and and Finn, four.
"We have randomised trial evidence that these methods result in children sleeping better, for longer, and there's no evidence that would suggest this is bad for your kid. In the short term, if anything, the evidence suggests sleep-trained kids are happier."
Oster argues that sleep training reduces maternal depression and increases marital satisfaction - yet too often, she says, parents' needs are not considered.
"There's sometimes the feeling that if something could have even a tiny positive effect for the baby - even if there's a huge cost to the parents - you should do it."
We all have a natural desire to do a good job, she says - but many of today's parents, particularly women and especially those who work, feel a pressure to be perfect. "Women who work outside the home can feel, 'I'm choosing my job over my kid, and so when I'm with my kids I'd better be the greatest mum ever, because otherwise I must not care about them'. The message of the book is to think about the family holistically."
Current debates about screen time also ignore the reality of daily life for many, says Oster. Recently, the World Health Organisation issued guidelines stating that under twos should not watch any devices at all, but many experts disputed the evidence on which this was based.
"This is an area where we don't have any evidence because [the technology] has not been around for long enough," she says. It's no doubt a bad idea for a child to watch hours of television, but she adds that the existing evidence is "reassuring", suggesting a little bit of screen time each day likely won't cause a problem. And again, it's important to be realistic: "a lot of us let our kids watch TV for half an hour so we can make dinner or have a shower - and making dinner and having a shower is important, too."
Oster lets her children, aged four and eight, play with their favourite app for six minutes as a reward for doing their violin practice.
Her book offers reassuring findings for "guilt-ridden mums", for example over breastfeeding which, Oster says, does have some benefits, including less diarrhoea for babies and some protection against breast cancer for mothers - but not as many as we're often led to believe. "People will tell you that breastfeeding will make kids smarter, or thinner or healthier in all these ways, but it isn't supported. There are correlations - breastfed children do have higher IQs - but that is very likely driven by differences across mums, not breastfeeding itself."
Cribsheet stands out from other parenting books in the way that it steers clear of recommendations and cast-iron guarantees, instead promising to arm parents with information to make the decisions that are right for them.
"In parenting, we get very wrapped up in the idea there is one right choice about everything." In truth, she says, "there are many ways to do it that are fine."
Parenting tips for a digital age
As well as making use of parental controls, further age-appropriate advice from Get Safe Online includes:
If your child is aged six to nine
• Agree a list of websites your child is allowed to visit and explain the kind of personal information they shouldn't reveal about themselves online, such as the name of their school or their home address.
• Set online time limits.
• Resist pressure to let them use technology or view certain online content that you don't think they're mature enough to use safely yet.
If your child is aged 10 to 12
• Set clear boundaries before they get their first "connected device" – don't wait until they're already using it.
• Start talking about "digital footprints" and how their online behaviour today can have future consequences.
• Be open about the kind of content they might see. Make it clear you're there to talk to them about it in a calm and non-judgmental way.
• Services such as Facebook and YouTube have a minimum age limit of 13 for a reason.
If your child is 13 or over
• Talk frankly about how they explore issues related to the health, well-being, body image and sexuality of themselves and others online. They may be discovering inaccurate or dangerous information on the internet.
• Review the settings on parental controls in line with your child's age and maturity. They may ask you to trust them sufficiently to turn them off completely. Agree in advance what is acceptable online behaviour.
• Routinely ask questions like: do you know everybody on your "friends" list; do you ever get messages from strangers; if so, how do you handle them; do you know anyone who has made plans to meet someone offline that they've only spoken to online; are people in your group of friends ever mean to each other online; has anyone ever been mean to you?
