My daughter will be getting her own Lego and possibly a selection of mine. I organized mine for the first time in my life last year. Some of the sets I've had since the very late 80s and early 90s. Those aren't getting lost :P
She can play with them supervised, but she'll have her own. This is all assuming she's even interested, she's only 2 so who knows yet.
Mine is also two and really into Duplo, so Lego will be a natural progression, especially considering that the blocks are compatible, so I wholeheartedly recommend it.
Also some the ones she's playing with are currently over 30 years old and still going.
She can play with them supervised, but she'll have her own. This is all assuming she's even interested, she's only 2 so who knows yet.