If anyone claims to be offering you completely unbiased political information, I would treat it with a degree of suspicion as people will have very different views about where the centre ground is and what amounts to extremism.
TheyWorkForYou www.theyworkforyou.com/mps/ is a helpful website which provides quite a lot of information on how people who have been MPs have voted. So if the person who has been your colleague's MP is standing again in this election, your colleague could look up how he/she has voted, which might be a decent start to deciding whether your colleague would like to see that person re-elected. However, TheyWorkForYou will not have information on a candidate who has never been an MP.
I would also suggest reading the parties' manifestos when they come out - should be easy to find by googling. It's important to understand that these are anything but unbiased! No party is going to admit to having policies that harm the NHS etc. However, if your colleague doesn't even think the manifesto looks good (ie when a party is advertising its policies in a favourable light) that suggests that party is not right for her.
The question of who to vote for is much more complicated than PersonaNonGarter suggests! This is because of the way the UK political system works, and it's important that your colleague understands this. Broadly, a party gets to form a government by having a majority of MPs in Parliament or (if no party has a majority, ie if there is a "hung" Parliament) by getting enough support from another party to be able to get its business voted through Parliament. The UK is divided into areas known as constituencies. Each constituency has one MP and that will be the person who gets the most votes in that constituency. That is known as the "first past the post" system, and it can produce strange results, eg imagine if a constituency has 60% of voters who want an anti-Brexit candidate and 40% who want a pro-Brexit candidate, but the anti-Brexit vote is split 50/50 between Party A and Party B whereas the pro-Brexit vote all goes to Party C, it is Party C's candidate who will become the MP for that constituency even though 60% do not like Party C's policy on Brexit. (I use Brexit to illustrate my point, but obviously in real life not everyone bases their vote on their views on Brexit.) In practice, in lots of constituencies, there are only two candidates who stand a chance of winning, so if A and B are the two candidates who stand a chance and you really don't like candidate A, you might think it makes sense to vote for candidate B who stands a chance of beating A even though the candidate you really like is candidate C. If your colleague looks up the 2017 general election result www.bbc.co.uk/news/election/2017/results, that may give her an idea of which parties stand a chance of winning where she lives (though there are a few constituencies where the 2017 result will not be a reliable guide, eg because a well known politician has decided to stand as an independent candidate rather than representing a party).
Your colleague may find that she lives in a "safe" seat, ie one where one party always wins with a huge majority, in which case she might as well just vote with her heart for the party she likes the best. As a VERY rought guide, if a party won a seat by more than 5000 votes at the last election, it's pretty unlikely, though not impossible, that it will get voted out.