70 is retirement age, and that means she would need cash for the next 20 years (if she lives to 90 years old). Most financially advisor would not recommend stock or even mutual funds for retirees, especially well into their retirement.
That said, the person has a windfall, so the situation may be different. It all depends on her current situation.
An advisor would most likely ask her about all her assets, how much is in stock, bonds, mutual funds, CDs, annuities, IRAs, 401(k), etc. as well as income such as Social Security, annunity, pension, IRAs distributions, etc.
And then he would build a few scenarios, based on how much money a) she would like to leave in her will, b) how much she needs to live on. He would probably build a schedule for her, based on assumptions such as average return of investments (for a retiree, probably something very conservative in the sub-6% range).
Most advisors would use standard scenarios -- meaning, they're not going to project her income/expense until she's 120 years old. Lifespan in the US is expected at 80, for example. That's not to say the advisor is going to say, "oh, you're going to die within 10 years anyway..." Most likely, the projection would be for about 15 to 20 years depending on the age of the person. I know my projection is based on a lifespan of 90 years with a retirement age of 65 -- that means I need to fund my lifestyle for about 25 years.
Most projections would aim at "depleting" the assets to give the person maximum distributions. However, again, it depends on the client's criteria -- how much to leave for the descendants, how much he/she needs to sustain her lifestyle (say, she wants to see the world or buy a condo in Fiji).
I don't think a financial advisor would ask about estate planning, unless that's something agreed upon to go over. That means, how much she's going to leave her son, etc. would not be discussed. It's her discretion. Instead, the advisor would most likely ask the following questions and base his projection on the answers -- usually with a mix of financial products that match the needs:
a) expected rate of return (normally 6-8%, low-end for conservative)
b) expected expense to support lifestyle (probably about 70-80% of pre-retirement spending adjusted by inflation)
c) desired liquidity (obviously, the rate of return would be greater if invested in long-term CDs or annuity or stocks, but the money would be tied down for a long period of time with hefty penalties)
d) tax brackets
e) inflation
f) assets (liquid, non-liquid, IRAs, properties, etc.)
g) income (SS, pension, IRA, etc.)