Given that the motive is family, I'm not sure I'd do anything especially protracted. There will almost certainly be better "buying opportunities" in the future, but good buying opportunities are usually attended by lots of pessimism, so if you're not sure you'd be willing to pull the trigger when everybody is telling you not to, I'd just go ahead and get it over with. I wouldn't bother with spreading out purchases from here. There's no reason to think the average price you pay will be especially better.

I will put in a plug, though, for a fund that I chose some years ago as a long-term holding, in lieu of RSP: Invesco's "growth at a reasonable price" [GARP} ETF, SPGP.

"The Invesco S&P 500 GARP ETF tracks an index that targets growth at a reasonable price. The index selects the 75 growth stocks within the S&P 500 that exhibit quality characteristics and have attractive valuations. Growth is measured as three year earnings per share, sales per share. Quality and value are assessed by looking at leverage, return on equity, and earnings to price."

invesco.com - Invesco sp garp ETF

Good luck,

Baltassar