The "motherly instinct" only lasts about as long as it takes the fry to swim away after she spits. After that any and all fry she finds she will try to eat. Once the male finished the spawning activities he will no longer have anything to do with the female or her fry.
If your tank has really good tiny hiding spots where the fry can hide for a good while (several months) some may survive.
If your tank has really good tiny hiding spots where the fry can hide for a good while (several months) some may survive.