Expressed as “the average number of babies that an individual woman needs to have for a certain population to stay the same size”, the replacement rate should not depend on population size, right?

If you express it as an absolute number (e.g. number of babies per year) than obviously it will depend on population size.

From what I understand, the replacement rate (expressed as the average number of babies that an individual woman needs to have for a certain population to stay the same size), depends mostly on what percentage of people die before they (can) have babies.