Now the DC condo is a very different question. While she could have gotten an exotic mortgage with interest only or something like that, she still would have had to make a substantial downpayment for it. I think the most likely explanation is that Hillary gave her the cash. Nothing illegal about it as long as she paid taxes on the income.
Also a good possibility is that Hillary has arranged some nice investments for Huma with her hedge-fund pals including Ron Rosenbaum, Norman Hsu, and Mark Lasky, the guy Chelsea works for.
If someone gifted her the money for the condo, then, with a top marginal tax rate of about 35%, for her to have cleared [after taxes] the $649,000 needed for the condo, the gift would have had to have been roughly:
I.e. if this was done on the up & up [at least as far as the IRS is concerned], then someone had to slip her a cool $1 MILLION!!!
[0.65] X GIFT = $649,000 GIFT = [$649,000] / [0.65] GIFT = $998,461.54
You know, the IRS is supposed to have software which goes bananas and which sets off all kinds of alarms if it detects that people are living way beyond their means like this.
And, no - college professors in the humanities & the social sciences do NOT leave million-dollar inheritances to their children.
If so, then all of their gifts have to be reported to the IRS.