To add new peds, use fastman's limit adjuster plugin.

Here is a tutorial:

https://www.youtube.com/watch?v=KSzGUf1qMMo&ab_channel=WhamDieMoe

Add this line into peds.ide file.

***, WFYBU3, WFYBU3, CIVFEMALE, STAT_SUIT_GIRL, busywoman, 120C, 0, man, 9, 2, PED_TYPE_GEN, VOICE_GEN_WFYBU, VOICE_GEN_WFYBU
***, DWFYLC3, DWFYLC3, CIVFEMALE, STAT_STREET_GIRL, woman, 181, 0, man, 1, 1, PED_TYPE_GEN, VOICE_GEN_DWFYLC1, VOICE_GEN_DWFYLC2

Don't forget to enter ID you want ped to have.