[81alum]

A friend insists that D1 womens scholarships are required to be for four years, either by Title 9 or NCAA.  Is that correct?  From this discussion it doesn't sound so.

No, but there are considerations. 
1) An increasing number of institutions, particularly at D1, are converting to 4 year scholarships in some or all sports.  So it could be true at whatever institution your friend follows.
2) The title IX rules I would have to speculate on.  For example, I would imagine that a university would be set up for a Title IX lawsuit if it guaranteed football scholarships only--without similarly guaranteeing an equal number of scholarships for women.  Women on one year renewables and men on 4 year guarantees would be problematic.
3) Stanford's policy is posted for all to see, and it is clear:

A financial award given to a student-athlete based upon athletic ability or sports performance is considered an athletic grant.  An athletic grant is awarded for a maximum period of one academic year and may be renewed annually.  Annual renewal of athletic aid is at the discretion of the head coach.

[81alum]

A friend insists that D1 womens scholarships are required to be for four years, either by Title 9 or NCAA.  Is that correct?  From this discussion it doesn't sound so.

No, but there are considerations. 
1) An increasing number of institutions, particularly at D1, are converting to 4 year scholarships in some or all sports.  So it could be true at whatever institution your friend follows.
2) The title IX rules I would have to speculate on.  For example, I would imagine that a university would be set up for a Title IX lawsuit if it guaranteed football scholarships only--without similarly guaranteeing an equal number of scholarships for women.  Women on one year renewables and men on 4 year guarantees would be problematic.
3) Stanford's policy is posted for all to see, and it is clear:

A financial award given to a student-athlete based upon athletic ability or sports performance is considered an athletic grant.  An athletic grant is awarded for a maximum period of one academic year and may be renewed annually.  Annual renewal of athletic aid is at the discretion of the head coach.