Here is a list of Jeannie Rice's age-group World Records and American Records.Note: Age group records are difficult to monitor and follow, as different organizations are in charge of approvals and postings.
Also, on the roads, the Marathon is the only distance recognized for age group World Records. (Whereas many distances are recognized for open World Records.) Most if not all of Jeannies American Records for road distances are also "World Bests" for her age group. That is, no one her age has run faster.
WORLD RECORDS (therefore American Records also), age group 75-79
Marathon = 3:33:27
1500 meters outdoors, track = 6:14:88
5000 meters, outdoors, track = 22:41.46
10,000 meters, outdoors, track = 46:53.07
AMERICAN RECORDS, roads, age group 75-79
1 mile = 6:44
10K = 49:14
12K = 54:50
15K = 1:13:23
20K = 1:37:46
Half Marathon = 1:43:09
25K = 2:02:12
30K = 2:26:51
Marathon = 3:34:32
WORLD RECORDS, ages 70-74
Marathon = 3:24:48
AMERICAN RECORDS, roads, ages 70-74
1 mile = 6:24
20K = 1:34:36
Half Marathon = 1:37:01
25K = 1:58:52
30K = 2:22:29
Marathon = 3:24:48
Here are some helpful websites for following age-group records. They may be slow to update.
World Records, Masters Athletics, Wikipedia
https://en.wikipedia.org/wiki/List_of_world_records_in_masters_athletics
American Age Group Road Records
http://www.usatfldrrecords.org/
World Age Group Records (Track and Non-Stadium, ie, Road)
https://world-masters-athletics.org/records/