I'd like to see your data. Silicon Valley aside, the trend for women with college degrees has been to postpone childbirth until around age 35. This isn't exactly news.
I don't have data for Silicon Valley, only anecdotal evidence. If you look at Indians and Russians around 30, they are mostly married and having/preparing to have kids. It is a well-known fact that immigrant fertility is higher in US than native fertility.
I don't know where 35 years at first child came from. This is way too high for an average, even among well-educated. There might be a trend but at that age you will have all kinds of problems even with modern advances in IVF.
