What gender do tu think his siblings are?

In my opinion, ALL of them are males.

Here, link it is mentioned about Scotland, Wales and North Ireland being his 'brothers'.

It has stated that Scotland is his brother in link

Many fans have expressed Scotland, Wales and North Ireland as males. Here is my best research yet :
link
(Scotland, North Ireland, Wales)

Overall, I think I'm right in saying that all of them are males. (How little research result I have... D:)

All male for sure. The creator of hetalia announced that he had brothers por the names of Ireland, Wales, and Scotland. :D

I think they are male, personally. They are commonly thought of as "The UK brothers", andif I'm not mistaken there have been refernces to them as "(England's) brothers" throughout hetalia... Like tu said, there was the one scene with "brothers". I would think that if it meant only 2 o so, it would mention there names, so I see "brothers" as the whole family (save Iggy himself).

Actually, it was Scotland, Wales and Northern Ireland who have been stated to be male. Ireland, on the other hand, is the only one who's gender is left to debate. In fact, the only thing that has been stated about him/her is that they are related to England.
In my personal opinion though, I believe that Wales has the most feminine charactisations out all of them.

Everything has been said, so yes, I'm pretty convinced they are all male. Here's another pic I already publicado at hetalia fan page.

Scotland would still be gorgeous if he was a boy o girl. God he's so beautiful.. *blush* That aside... *ahem* I believe they are all male so...

As far as I've seen, they're all boys. I believe in the anime he actually mentioned having brothers at some point, sorry I can't remember specifically when though

They are all male! I believe this is because the most popular one are the male ones. Plus the male ones are the ones in the comics. And I totally agree the female ones of them look awful...

All of them are brothers, however Wales might be portrayed very female qualities because of old traditions with that Wales use to and still have.
Since the Welsh are known to sing constantly so they will probably give him a very enthusiastic approach to canto and being proud. Also during Ancient Celtic times being a poet was a highly respected job and is still highly respected in Wales today.
Its obvious that Scotland is male and is the eldest and most likely England will be the baby of the brothers when looking from an historical perspective its most likely that Ireland (as a whole) will be the segundo oldest and then Wales being just slightly older than England.
However, with regards to the gender of Ireland it will very much depend on what time period they set the brother being in. If its pre-WW2 then its most likely that it will be a male Ireland... but after WW2 there was the Irish war which divided Ireland (officially in 1998) therefor making a Northern Ireland (which will not be the same as the original Ireland) and then the debate over gender of Northern Ireland could be debated

All male, for sure.. N ireland, S ireland, Sealand, England, Scotland, Wales. All brothers

I think they are all guys but hetalia could always use más Female nations

I think that they'll all be males. I have reasons, but I also have this instinct/ hunch, which is a surprisingly stupid thing to rely on but oh well :d

I know I'm answering like really late, but Scotland, Wales, and Northern Ireland are all males. Himaruya-san even made a sketch of them. I'm not sure who's who though.

All Males that I am pretty sure about.

I believe that England's siblings are that wales,Scotland, and n.ireland are male yet the rebuplic of Ireland is female.

I feel like they would all be guys, but i would wish there would be at least one girl, I could mostly imagine ireland being the girl. There is so many male characters in hetalia, -and it is sort of unfair