Since their basic needs are already met, it gives them a huge amount of leeway.

• They can be more aggressive - higher risk by way of wider range of outcomes but expected (or "average" long term) return being higher; or
• They can be more conservative where the range of outcomes is narrower but also the expected (or "average" long term) return being lower.

If they're more interested in spending it enjoying life, and having more money for potential medical issues, I would go more conservative.

If they're more interested in leaving an inheritance I would go for a bit more aggressive.

Whichever they choose, consider the tax consequences as there is likely a good way and bad way to set it up as redditau34 noted.