Qwerty, im afraid about your application. As per the UKBA Family Visitor Requirement, the family member you are visiting MUST be a British Citizen or Settled in the UK. I think your Mum is neither British Citizen nor Settled in the UK since she has Leave to Remain visa only. Stay optimistic, don't lose hope. Best of luck dear.
When we sponsored my uncle for a family visit visa, I was holding a Fiancee Visa and his family visit visa was approved. If Qwerty can show proofs that she will return to the Philippines, her mother's current visa won't be an issue.
-=rayna.keith=- ...When you realize you want to spend the rest of your life with somebody, you want the rest of your life to start as soon as possible...