An over-tired baby is really, really, really hard to get to sleep. Whereas a just-started-feeling-tired baby will be much, much easier to get to sleep.
Good seep promotes better sleep. If you ensure baby is getting naps frequent enough and for long enough, then baby will start sleeping more and with better quality sleep.
Your OP reads completely the wrong way around. I would not start keeping a tired baby awake until the later developmental changes around 1y-2y old.
She cries to feed and sleep only an hour after waking but will only sleep 30 minutes. I've tried keeping her awake longer as I know 2 hours is recommended but she's distraught and as soon as I feed her then she's asleep
Sounds like trying to fit a square peg into round hole.
If baby is wanting short naps, then they have to be frequent to avoid being over-tired. Keeping baby awake will not teach her to sleep longer, it will just makes the whole situation worse.
With 30 minute naps, I wouldn't expect more than 90 minutes awake from when last woke - all the way through he daytime - 30ish mins asleep, 90ish mins awake, 30ish mins asleep, 90ish mins awake, 30ish mins asleep, 90ish mins awake, 30ish mins asleep, 90ish mins awake... and so on.
Baby's naps can be extended at this age. It is when baby's naps extend that is logically follows that if baby is asleep for more like 2 hours, then the time awake will naturally lengthen and so naps will be less frequent.
This stage comes by baby being taught to sleep for longer - by having re-settling techniques that you use s soon as baby stirs to help her go back to sleep for another sleep cycle. So to solve this your focus needs to be in extending naps, not lengthening awake time.
She does get fed to sleep a lot but this hasn't caused problems previously and in the day WILL NOT NAP without boob
This will be the problem. Baby hasn't been taught to sleep independently and so she cannot extend her own nap from one sleep cycle into another through the daytime, without your help.
Could you develop a settling method that you use while baby is in the cot? Like shushing, patting, stroking, tickling, firm hand on chest, dummy, comforter toy - any and all of these will help baby learn to go to sleep in the cot. Then the dummy and comforter help long term to allow baby to gain comfort and security without your presence when waking.