LNERGE

Make a train shaped rattle one of the early toys then a Brio set as the first more train set like purchase, but regarding the Brio not for a year or so yet.

Give her the gift of the joy and encouragement of creating with her own hands.... railway modelling is just one way of expressing that joy. 

Once she's crawling, you want the ELC Happyland Train. Here's an unboxing video: 

twenty or more years ago, we had two sets, including points and a diamond (well, square) crossing. It could be set up with two trains circulating in opposite directions on a dog-bone layout with passing loop. With care, it could run for ages without a collision! You can probably get extra track or complete sets second-hand.