Another "Maternal" theory was not to let a baby too early stand up in your lap, holding onto their hands and let them bounce- they will go "bowlegged"
Another one of grandma and my great aunts theories was if you tickled a baby too much, where they just giggled and giggled you would make them stutter. Taking their advice, many time we tickled our babies, leaning over them as they giggled and kicked, cooing over them and saying " you're gonna stutter, your gonna stutter!" ( both my kiddos have fine speech)
And of course the ever popular, "It's fun until someone gets hurt!" proclamation generated with my Grandma B. - haven't used that on my girls- both have been in karate and the oldest is a brown belt- so they would probably look at me really weird- but I do think of my Grandma B when my girls are goofing around- and miss that she isn't sitting in a nearby chair, " waving her hand their way and proclaiming the "its fun til someone get hurt" speech- she'd be sipping her afternoon coffee and nibbling on her tiny piece of snicker bar, she could make a whole bar last for a whole week, ( that is all Danish blood if you are wondering- practicality, coffee, sweets). Boy do I miss her- Danish is having a lot of mothers, grandmother and aunts "helping" you as a young mother- funny I feel privileged to have had that, learned a lot from them and at the same time don't wish that on my daughters when they are mothers- maybe by the time I'm a grandma- I'll of forgotten the annoying part of it and chime in with the aunts telling the young mothers to not let their husbands throw their kids up in the air cause they'll dislocate a shoulder.