Well, RIANNE MALLOWS, all I can say is that your mother is just concerned about you, and yakking on what she deems to be in your best interest. Yan naman ang role ng mothers di ba, ang impart to you the Big Lessons she learned in life. Take it or leave it, it's your decision.
One time, tell her though that whatever financial arrangements you and your hubby have... that is something she cannot do anything about. Such arrangements are unique to each couple.
About asking for a bigger allowance, or padding the household expenses...
IMO, the common phraseology is: pagkupit sa asawa. hehe
IMO, it is generally resorted to to re-allocate family funds use, coz some things take long to explain or cannot be explained away easily.
Who am I to say if such is good or bad? Everything can be qualified either way.

Now, do you need to do that?
Only you can say, insite of your public protestations about the fairness and generosity of your hubby, your toned down personal lifestyle, etc etc
Why did you not charge/send the entire bill of P100thou to your husband, instead of secretly shouldering half?
Face the truth, and face your fears or anxieties.
Now, if all is at par, but you need a bigger psychological financial cushion... there are ways to go about it without being sneaky or hiding info from your husband. Have him set up a separate account for say your kid's college fund, to which he regularly deposits a fixed amoiunt.. then you keep regular track of that.. malay mo one day whooosh! withdrawn pala lahat....
Have him commit to a big asset investment, say a condo, another lot.. whatever, that will make him commit to a regular stream of payments...
The thing is, the less disposable income he controls, the more comfortably you sleep each night.
But the best insurance you can get for yourself, darling, is financial self-empowerment. Look for a business you can run from home, or manage while letting you still take care of your kid - as your husband prefers.
Find ways so that you not only have savings, but that your savings earn more for you... turn-over is what preserves your funds in the future, otherwise inflation just erodes your next egg.