Can I challenge my mum's will?

[Disinherited]

Hello.

I am no longer in contact with my mother. We have not spoken for 3 years. When the breach happened, she told my brother she was going to disinherit me. She's always been a bit obsessed with money and had threatened this in the past to me and my brother if we "stepped out of line". She told my brother she was going to leave her estate 50% to him and 25% each to my two children, her GC. They are currently 6 and 9.
If she has indeed done this and died while they were still young, would I have the right to challenge it? Is she likely to have put it in trust for them or something? I ask because it would be around €100,000 between my children (so, €50,000 each). If I could challenge it, I could use some to pay off our mortgage and therefore be able to give them a much better life, but still be able to have them inherit quite a bit. If they were adults, obviously then that's different. Obviously, she could live for years yet, or not even have done this, so it's all hypothetical.
If you challenge a will is it a long, complex process?

Namechange fail. Oh well.

I think I find it a bit odd that you are thinking about challenging her will when she has not died (and perhaps not even ill?)

I was thinking about it because my brother mentioned it. Nevermind. Sometimes, however unjust it all is, the only way to go is to forget it all. That's what she wants anyway with threatening to do it, she wants to drive home that I'm not part of the family. Fair enough.

I'm going to leave this now. Thanks for all the replies.

There are several grounds on which you can contest a will in the UK: incapacity, negligently drafted, fraud, undue influence, lack of knowledge and "lack of due execution".
There was a case of a woman (Ilott) contesting her mother's wish to leave her entire estate to charity. She contested it under the Inheritance Act 1975, claiming that she hadn't received adequate financial provision from her mother's estate - she was living on state benefits and in her 50s. The initial £50k awarded by County Court was pursued further by Ilott and whilst the Court of Appeal increased the award to £163k, the Supreme Court reversed the decision back to £50k. This was because some of the mother's estate equated to wealth from Ilott's late father.
Costs from contesting a will aren't automatically recovered from the estate and being that this is hostile litigation, it is a costly and very lengthy process. Many people discover any financial gain is eaten up by the costs of the specialist legal advice they have to secure. Illot's mother died in 2004 and it wasn't until earlier this year that the Supreme Court made the final ruling.
You mention having a mortgage which suggests you are capable of looking after yourself and your family financially therefore it sounds unlikely that the grounds on which Ilott made her claim would apply.

At least your mother has chosen to include her grandchildren - she could cut them out of the will.

You can not use your children inhertence to pay off your morgage unless you also sign over the same % to them aka you pay off 50K morgage you would have to but the house into their names as well (aka OP children now own a share of house etc) otherwise you would be done for fraud.

Under 18s can't own property so that isn't possible.

If she dies in NI the following will apply

www.legislation.gov.uk/nisi/1979/924