So, I feel that Ada will be increasingly less usefull as you go down the eras:
- Antiquity: powerfull, since you need science masteries for the codex, and civic masteries for unlocking the wonders. So she will be rather impactfull.
- Exploration: for tech you want to beeline shipbuilding (to start your treasure fleets), and fo civics, well, there are no real target pas piety, so why not... But you sure won't want to take time searching for tech masteries before a third or more of the age is up... Since civics that increase the settlement limit tends to be masteries, Ada will still be somewhat usefull...
- Modern: what masteries??? Let's be frank: science legacy want to beeline the relevant techs, economic want their factory ASAP, military want their unit upgrade and plane now, etc... So you may not be doing more than a handfull of science masteries at best... As for civics, the ideologies are not masteries, and you want to hit Egemony fast to snatch the last relics you need. So, again, no masteries... So Ada will be rather useless...
As for civs, except for the obvious Mayan powerhouse (that already get science when completing a civic, and vice-versa), there does not see to be a particular fit beyond the obvious "take a science/culture civ"... However, some things are to be noted:
- Civs that have a lot of materies in their unique civics will be "more usefull".
- Civ that are particulary proficient in culture/science will be able to use that to compensate for the other production, which is still nice.
I won't say she is a bad leader, but it is sad to have her worth disminishing as the ages go on...