Herbert, Henry & Sylvia Bender circa 1918 with mystery aunt

[Gadget]

That's ever so good of you, Peter.

Given the various images that you've produced, I'd say that the shape of the face and the other features do suggest that it's the same woman 

[jim1]

The date for pic. 1 is about right.
It looks from around WW1 into the 20's making the lady in question
25-30.
The lady in this looks in her 50's.

[Chrissyan]

Wow, thank you all for your very valuable input  Especially Japeflakes, Gadget, Hoobaloo, McGroger, I am very, very grateful. The jury is still out, however I am inclined to think it is is her (those cheekbones!) 

[jim1]

however I am inclined to think it is is her

That's called confirmation bias.
Does she look 25-30 to you?

[Gadget]

I think your 50 is being kind, Jim 

[Chrissyan]

In later life, people do acquire bags under their eyes    Also, note the high cheek bones.

I think your 50 is being kind, Jim

Gadget

I agree wholeheartedly with both of these comments gadget   

[Chrissyan]

The date for pic. 1 is about right.
It looks from around WW1 into the 20's making the lady in question
25-30.
The lady in this looks in her 50's.

That's called confirmation bias.
Does she look 25-30 to you?

Sorry jim1 I think  I have mis-understood you if the lady on the moors with the children is Hilda, it would make her 27 when the photo was taken,do you think she is much older than that?

As for the older photo of who I do know is Hilda, I have just received it from a 2nd cousin once removed in Canada, who I contacted because we are a DNa match. I have no idea when it was taken.

[jim1]

Much older than that.
50-60.

[Gadget]

I would say at least mid-60s. However, I look younger than her  and I'm mid-70s 

I'd say late 20s for the first pic.