I suppose that would depend on how you define social reform. Ireland (both bits of it) is actually fairly left-leaning in both economic and social policy OTL. The most "right wing" parties -Fianna Fail, Fine Gael and DUP are all very centrist/soft left by UK or American standards. I have mentioned in other posts that it is a mistake to see the DUP as a far right party -sectarian version of "Blue Labour" would be nearer the mark. So very pro economic intervention by the state, urban renewal, child benefit, healthcare provision, state funding of education. Now we don't know who might be butterflied away but (NI) Lord Craigavon, Lord Charlemont, Sir Crawford McCullagh, Maynard Sinclair, "Wee Joe" Devlin, Harry Midgeley, Paddy Devlin, Gerry Fitt, John Hume were all of that view. ROI, Collins, deValera, Lemass, Lynch all likewise. Again, viewing Stormont as a right wing cabal is misleading, anti- Catholic yes, but they introduced all the same welfare state legislation as in GB (not replicating that relating to abortion and homosexuality only) and were vigorous in slum clearance and infrastructure investment and actually built a new city (Craigavon). Even the "Big House" Unionist leadership were very much One Nation Tories.
Now TTL Ireland wouldn't be openly sectarian but it would be religiously observant and that would be used as a political unifying factor.
So I suspect that the British state (national and devolved) might have withdrawn more slowly from the direct management of the economy than OTL and health and social services would be generous but judgemental. Good child benefit for instance but not available to unmarried mothers. Good healthcare but abortion only when mother's life in danger. Good public housing for respectable God-fearing families. Unmarried mother or same gender couple? You won't be first on the priority list (or second.........or fifty seventh...)
First divorced man in British cabinet (one of the Wedgwoods in Ramsay McDonald's Cabinet I think OTL) would not have been in the 1920s -more likely the 1960s or 70s. And probably not a great place to be LGBT or an unmarried mother up until the decline in political influence of the Catholic Church. So 1990s/2000s would be TTLs Sixties. Against that, probably not the outright censorship of books on the Catholic Church's proscribed list or contraception actually being made illegal.