Some parents aren't relaxed or approachable - I'm surprised how many people suggested that my household shouldn't be seen as a source of tampons and pads for daughter's friends. One of those friends lives 25miles away from school - erm, she could get caught out. One of the others was abandoned by one parent, the other has now gone and the girl is living in accommodation for people who have been chucked out by the council. It's grim.
I those qualifiers of being a long way from school, and difficult family circumstances do change my views a fair bit about the reasonableness of these girls using your families supplies. I wouldn't have had any excuse as a teen for more than emergency usages or for not asking my mum to help me return a box if I'd used loads but I know my mum would do that - ESPECIALLY if I'd borrowed from someone who didn't have a lot of money at home.
I am lucky my parents were approachable, my two sisters and I knew where mum's stuff was kept and as an ex-midwife she had medical books everywhere. She also did a lot of our school (yr 6 in primary) sex education because of her nursing and showed the teacher up as wrong on a fair few things. Mum used to get asked questions by my classmates whose parents hadn't told them. There were more than three or four girls who at 11 didn't know that periods even existed which for 1991 was a bit shocking to mum and our family. It's sad that those sorts of issues are still awkward or untalked about now.
Saying that, my college friend is a gay guy who despite medic parents had never seen a tampon at 17 and didn't know how periods or women's biology worked. Well, until I got a pen and paper out and insisted it was Things Everyone Should Know TM and I wasn't standing for any of this mysogynistic "eww periods" crap! It seems that he had two brothers and his mum had her own bathroom so he never saw periods stuff and he wasn't the sort to read his parents medical books - especially the female bits!
I ain't going to tell either of them that they can't help themselves; it seems ridiculous, if I couldn't afford to 'supply' them I could just cut out a bottle of wine per week. . . .
True and yes is a much worthier cause. It may well be worth letting your teens know about mooncups and similar alternatives so if the others have the chance they can find a method which once invested in doesn't cost any more for several years. But your lot may be a bit young for the alternatives and I personally had disability reasons the mooncup didn't work but I know a lot of people who save £3-35 a month that way which is loads on a low income.
We've not really needed to have many conversations about sex ed - we do talk a lot about responsibilities, the effects on girls of youthful pregnancies. The boys are more of a worry - less inclined to talk and more arrogantly full of themselves.
I think the emotional/society/individual cost of stuff is far more useful, anyone can find stuff innabook it's the nuances and thinking about things in advance so if in situation of complex you have some thought which is prethought to fall back on.
One thing my mum did badly was threaten us about "if you become pregnant" which scared us more than was helpful - she has acknowledged that tho and realises she took that a tad too far! I agree girls are probably easier cos they do know and fear pregnancy and it's easy for lads to see others getting away without penalty cos so many lads don't stay involved if they get a girl pregnant and so many lads' families let them get away with that!